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Big birds in the Cretaceous of Central Asia: say hello to Samrukia


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Two possible body shapes for the new bird - read on. Images by John Conway.

It’s not uncommon in palaeontology to discover isolated, even fragmentary, specimens that seem not only to represent new species, but also to tell you a lot of interesting stuff. Today sees the publication of a new paper in Biology Letters in which I and a team of colleagues describe a remarkable new Cretaceous bird, discovered a few decades ago in the Kyzylorda District of Kazakhstan (Naish et al. 2011). Represented only by the two halves (or rami) of its large lower jaw, this fossil provides new information on Cretaceous bird evolution and diversity, and perhaps on the composition of Cretaceous faunas and ecosystems.

The adventure started back in August 2010 when Pascal Godefroit of the Institut royal des Sciences naturelles de Belgique (IRSNB) in Brussels began corresponding with Gareth Dyke and myself about this most interesting specimen. Complete, in great shape and just over 30 cm long, it possessed a rounded, ‘U’-shaped symphyseal region (the section where the two rami meet anteriorly) and was completely toothless. Seen from above, it looked superficially like the lower jaw of a caenagnathid oviraptorosaur.

While the jaw clearly belonged to a theropod dinosaur, it was also evident right from the start that it was specifically from a bird, and actually not from an oviraptorosaur at all. The mandibular cotyle – the concave region of the lower jaw that articulates with the quadrate bone – was very obviously biconcave, with a diagonally aligned ridge separating the two parts. Mandibular fenestrae (window-like openings in the outer wall of each ramus) were totally absent, the bones were all fused together, and a large, apparently pneumatic opening was present on the posterior, post-articular region of each ramus. Gareth and I needed to check it out in person, so we made the trek to Brussels to examine the specimen first hand (and a trip to the IRSNB is great, especially if you’re interested in iguanodontians).

The jaw as it originally appeared. It's huge! (for a Mesozoic bird).

Sure enough, we could confirm that it was indeed a bird jaw. A big one. Those biconcave cotyles, fully fused-up bones, pneumatic foramina and so on all screamed ‘bird’. One or two of these features might be present in members of other clades, but not all of them.

Gareth codes the specimen for analysis. How did we do science before laptop computers?

So ideas that the jaw might be from any of the other Mesozoic tetrapod groups known to have evolved toothless rami (like turtles or pterosaurs) could be immediately eliminated. What about the general oviraptorosaur-like demeanour of the specimen? By now it was now obvious that the specimen was only superficially oviraptorosaur-like, and all because of that ‘U’-shaped, toothless symphyseal region. And this was a painted plaster reconstruction! Yes, it seems that someone (we don’t know who) deliberately modelled the symphyseal region after that of a caenagnathid oviraptorosaur, perhaps because they assumed that this is the sort of animal the jaw rami belonged to. In all of its other details, the jaw is emphatically unlike that of an oviraptorosaur, and it also differs substantially from the lower jaws of the other theropod clades that evolved toothlessness (ceratosaurs and ornithomimosaurs).

With the fake symphyseal region removed, we were left with two elongate rami. These are toothless, but – lacking the animal’s real symphyseal region – we can’t be sure that the jaws were completely toothless since at least a few Mesozoic birds (Jeholornis prima is the classic example) lack teeth in their rami, but still have a few teeth at the jaw tips.

The partial lower jaw rami of our new giant Cretaceous bird. (a) posterior region of left ramus as seen from above. (b) posterior region of left ramus as seen from below. (c) right side of lower jaw, seen from the outside. (d) right side of lower jaw, seen from the inside.

Placing the bird in the tree

By eyeballing the specimen and comparing its characters with those of other theropods (and other animals) we were already confident that this was a big Cretaceous bird. But what sort of bird? The large pneumatic foramen at the back of the jaw suggested that it was close to Ichthyornis and neornithines. Gareth and I coded the specimen and threw it into a large cladistic analysis of Mesozoic birds (O’Connor et al. 2011). It was resolved as a member of Ornithuromorpha, the avialian clade that includes crown-birds (Neornithes), Patagopteryx, Vorona, Ambiortus, Apsaravis and the YixianornisYanornis clade.

In order to be even more confident about this phylogenetic placement, we worked with Andrea Cau (of Theropoda) to include the specimen within a far more extensive analysis of all of Theropoda. The placement was exactly the same: the specimen not only grouped within Avialae (the bird branch of Theropoda), but closer to neornithines than to confuciusornithids or enantiornithines, and somewhere round about the ‘base’ of Ornithuromorpha (Naish et al. 2011).

Archaeopteryx not a “bird”?

As an interesting aside, one peculiarity of our tree is that Archaeopteryx was recovered as a basal paravian, in a polytomy with scansoriopterygids, deinonychosaurs and avialians (Naish et al. 2011). According to this tree [shown below: click to enlarge], neither Archaeopteryx nor scansoriopterygids are members of Avialae.

Life restoration of Xiaotingia zhengi, (c) Xing Lida and Liu Yi.

As you’ll know if you’ve been keeping up with the news, Xu et al. (2011) recently published the new Liaoning maniraptoran Xiaotingia and recovered a phylogeny where Archaeopteryx is a deinonychosaur, not an avialian (Xu et al. 2011). Hence all those headlines like “Archaeopteryx knocked off its perch” (groan), “Flap about Archaeopteryx” (double groan) and so on. We didn’t include Xiaotingia in our data set and our result is completely independent of Xu et al.’s: had our paper been published just a couple of weeks earlier, we’d have been first to recover Archaeopteryx as a non-avialian.

Our 'whole theropod' analysis, with (again) our new big bird (Samrukia) within Ornithuromorpha. Some other taxa of special interest are marked with arrows, including Oviraptorosauria, Archaeopteryx and Avialae. From Naish et al. (2011, online supp. info).

Note that our result actually isn’t the same as Xu et al.’s seeing as, unlike them, we didn’t find Archaeopteryx to be a deinonychosaur. I’d also like to take this opportunity to note that the moving of Archaeopteryx out of Avialae really isn’t a big deal, or a surprise – it amounts to a shift of a node or two, and quite a few theropod workers have been saying for years that it’s probably only a matter of time before phylogenies start finding Archaeopteryx to fall outside of Avialae. Given what we now know about early dromaeosaurids, troodontids and oviraptorosaurs, and about Anchiornis, scansoriopterygids and so on, it’s clear that working out the relationships among these confusing and often very similar feathered little maniraptorans is not going to be easy. Indeed, don’t go thinking that the notion of a non-avialian Archaeopteryx is necessarily here to stay!

Aves or Avialae? (assuming that the taxon shown is a member of the bird branch of Maniraptora). People are still fighting. Image by H. Raab, from wikipedia.

Fans of phylogenetic nomenclature will note that we use the term ‘Aves’ throughout our paper (Naish et al. 2011). I really dislike the use of the term Aves for the lineage that includes neornithines and all maniraptorans closer to them than to deinonychosaurs: Avialae, in my opinion, is superior since it should be understood – right from its earliest use (Gauthier 1986, p. 36) – to be maximally inclusive (Aves, in contrast, has been restricted by some authors to the avialian crown). However, some people who work on fossil birds (including one of our reviewers) really hate the term Avialae, and in this case we decided to make our lives easier and just change our favoured nomenclature (I won’t bore you with details of the long, tedious, pre-publication history of this paper. As is usual these days, it went round the houses before finally being accepted at Biology Letters).

Anyway, both our ‘birds only’ and ‘total theropod’ analyses recovered the same phylogenetic position for the Kazakh giant. Furthermore, this position matched what we had already concluded from our non-computer-assisted assessment of the specimen’s character distribution. This is far from the first time that I’ve had a parsimony analysis produce results that mostly matched the conclusions already reached by unassisted human brain power – a very similar thing happened with the neosauropod Xenoposeidon (Taylor & Naish 2007).

Even though we only have partial lower jaw rami for our new ornithuromorph, a few unique features were immediately apparent. The specimen possesses elongate sulci on the medial sides of its rami and a shelf-like lamina connects the bone next to the bottom part of this sulcus with the medial cotyle (see close-up photo below). Furthermore, the anatomy of the bone around the specimen’s mandibular cotyles is unique and distinctive.

Close-up posteromedial view of the articular region of the specimen's left ramus, showing the diagnostic medial sulcus and associated structures.

While I agree with the majority of my colleagues that naming new taxa for very scrappy remains should be avoided where possible, I’m also of the opinion that you should give names to things when you can clearly distinguish them from other things. If, in a fossil animal, you find autapomorphies – that is, unique, previously unreported anatomical features – you’re obliged to name what you have. Based on incomplete mandibular rami or not, our giant Kazakh bird jaw therefore needs a name, and hence Samrukia nessovi was born. The generic name is a nod to the Samruk, a mythological, phoenix-like Kazakh bird, while the specific name honours the contribution to Central Asian vertebrate palaeontology of the late Lev Nessov (1947-1995).

Big – but how big?

The most remarkable thing about Samrukia is its size. The longest of those incomplete rami is a whopping 27.5 cm long, and even the anterior-most tip of this ramus appears well short of the mandible’s original symphyseal region. The entire mandible was, therefore, damn near certainly over 30 cm long: the cranium was likely longer, since that’s typically the case. So, this Cretaceous bird had a skull over 30 cm long.

Two possible body shapes for the gigantic Samrukia, with a human and 'normal-sized' Mesozoic bird for scale. Image by John Conway.

How big was the whole animal? That, unfortunately, is just about unanswerable, since it’s impossible to work out anything for certain about the overall appearance of a bird when all you have is its (incomplete) lower jaw. We can’t even say whether Samrukia was flightless or flight-capable – there aren’t any reliable inferences you can draw on this issue from jaw structure, nor from bone histology, bone wall thickness or anything like that. At the moment, it’s possible that Samrukia was a large, perhaps condor-shaped flying bird with a giant wingspan. Based on rough comparisons with other big, flying birds, it could have had a wingspan of 4 m or so and weighed at least 12 kg (Naish et al. 2011). But it’s equally plausible that it was a flightless bird shaped like a ratite, gastornithid or dromornithid; if so, it could have weighed more than 50 kg (Naish et al. 2011) and been somewhere between 2 and 3 m in standing height. These suggestions are highly speculative and, as we state in the paper, we can’t say anything with certainty about the size or appearance of this bird in the absence of better remains.

The majority of Mesozoic birds, and certainly those known from terrestrial environments, were small animals less than about 2 kg in mass and typically similar in size to modern finches, thrushes or crows. Note that some of the marine hesperornithines were very big, hence my specific reference to ‘terrestrial’ Mesozoic birds throughout this discussion. I should also note (given the fondness blog readers have for pickiness) that a few Mesozoic terrestrial birds, like Sapeornis and the enantiornithines Enantiornis, Martinavis and Avisaurus, had wingspans of between 1 and 1.5 m. Based on comparison with similar-sized modern hawks, eagles and gulls, such birds would still be less than 2 kg in mass.

We haven’t forgotten you, Gargantuavis

The Gargantuavis holotype synsacrum and partial pelvis (r) and referred femur (l). Images by Ghedoghedo, from wikipedia.

Anyway, Samrukia was obviously a giant, and hence very special. But we’re careful to note in our paper that it isn’t unique. Gargantuavis philoinos from the Late Cretaceous of France is already well established as a terrestrial giant (Buffetaut et al. 1995, Buffetaut & Le Loeuff 1998, 2011). So, Samrukia isn’t the first giant, terrestrial Cretaceous bird; it’s the second.

Actually, when we started our research on Samrukia a minor disagreement over the avialian status of Gargantuavis was occurring – some palaeornithologists were suggesting that it might not be a bird at all but actually an azhdarchid pterosaur (Mayr 2009). We didn’t agree with this (in my opinion, Gargantuavis has always very obviously been a bird – and I speak as someone who works on azhdarchids as well as on Mesozoic and Cenozoic birds). However, it seemed only appropriate to note that the status of Gargantuavis was at least under suspicion, or under discussion, at the time of writing; the best cause of action was to say that Samrukia confirmed the existence of giant terrestrial birds in the Cretaceous. And while our paper was in review, a new article on Gargantuavis appeared in which Eric Buffetaut and Jean Le Loeuff argued strongly against suggestions that Gargantuavis might be a pterosaur (Buffetaut & Le Loeuff 2011).

Speculative reconstruction of Gargantuavis, by Hyrotrioskjan. While shown here as an ostrich-like, small-headed form, it could have been big-skulled like a gastornithid or dromornithid.

The phylogenetic position of Gargantuavis is uncertain, but various of its characters suggest that it might be a basal ornithuromorph and hence from the same approximate region of the avialian cladogram as Samrukia. Could Gargantuavis and Samrukia be close relatives, or even the same thing? For now, we lack evidence to evaluate this idea further, but I’m certainly not averse to the idea that they could be sister-taxa. As we state in the paper, however, “the restriction of Gargantuavis to a younger, western European fauna with no close biogeographic ties to the Santonian-Campanian of Central Asia renders it unlikely that Gargantuavis and Samrukia are congeneric” (Naish et al. 2011, p. 3).

Friends and neighbours

Map of the Republic of Kazakhstan, from Naish et al. (2011). Several sites in the south of the country are well known for yielding Cretaceous vertebrate fossils, notably Akkurgan (marked with a star), Shakh-Shakh and Syuk-Syuk.

What I regard as one of the most interesting things about both Gargantuavis and Samrukia is that neither was living in isolation on some Cretaceous island. Rather, both were living alongside assemblages of non-avialian dinosaurs and also alongside large pterosaurs. Samrukia comes from the Bostobynskaya Formation (also known as the Bostobe Formation). Hadrosaurs and tyrannosaurids are known from the Akkurgan locality in Kazakhstan that yielded Samrukia, but ornithomimids, therizinosaurs, caenagnathids (how ironic), dromaeosaurids, ankylosaurs and rare sauropods have all been reported from the Bostobynskaya Formation as well (Dyke & Malakhov 2004, Averianov 2007a). All should be imagined as close neighbours of this giant bird. The azhdarchid pterosaur Aralazhdarcho is also from the Bostobynskaya Formation (Averianov 2004, 2007b).

Virtually all of these Kazakh fossils come from floodplain habitats, but associated wood fragments indicate that forests were present nearby. Sharks, salamanders, turtles and the remains of other aquatic organisms show that pools, lakes and large, occasionally quasi-marine meandering rivers were also present across the region.

Samrukia (in both speculative volant and flightless forms) to approximate scale with some contemporaneous taxa: a therizinosaur, tyrannosaurid and azhdarchid pterosaur. Samrukia images by John Conway, azhdarchid by Mark Witton, therizinosaur and tyrannosaurid by me.

What does this mean for Samrukia, and for the composition of Cretaceous ecosystems as a whole? If Samrukia was flightless, maybe it was able to avoid tyrannosaurids and other predatory theropods by being cursorial, but if it was flight-capable then we have to imagine it soaring over the heads of its terrestrial cousins and literally sharing the skies with similar-sized azhdarchid pterosaurs. Overall, the discovery of Samrukia provides additional evidence for a more diverse Late Cretaceous world than the one we’ve been inclined to imagine. The Late Cretaecous continental realm wasn’t a ‘non-avialian-dinosaurs-only theme park’; there was ecological ‘space’ for big birds and also for reasonably big, terrestrial crocodilians, squamates and even synapsids (and if any of this sounds familiar, it’s because I covered the same subject back in 2007 when talking about Mesozoic sebecosuchian crocodilians).

So, hello Samrukia, welcome to the ranks. What’s next? As regards Samrukia… as is so often the case, we need more material before we can go any further.

For previous Tet Zoo articles on Mesozoic birds, see…

While I’m here, remember to follow me on Twitter: @TetZoo.

Refs – -

Averianov, A. O. 2004. New data on Cretaceous flying reptiles (Pterosauria) from Russia, Kazakhstan, and Kyrgyzstan. Paleontological Journal 38, 426-436.

- . 2007a. Theropod dinosaurs from Late Cretaceous deposits in the northeastern Aral Sea region, Kazakhstan. Cretaceous Research 28, 532-544.

- . 2007b. New records of azhdarchids (Pterosauria, Azhdarchidae) from the late Cretaceous of Russia, Kazakhstan, and Central Asia. Paleontological Journal 41, 189-197.

Buffetaut, E., Le Loeuff, J., Mechin, P. & Mechin-Salessy, A. 1995. A large French Cretaceous bird. Nature 377, 110.

- . & Le Loeuff, J. 1998. A new giant ground bird from the Upper Cretaceous of southern France. Journal of the Geological Society, London 155, 1-4.

- . & Le Loeuff, J. L. 2011. Gargantuavis philoinos: giant bird or giant pterosaur? Annales de Paléontologie 135-141 doi:10.1016/j.annpal.2011.05.002

Dyke, G. J. & Malakhov, D. V. 2004. Abundance and taphonomy of dinosaur teeth and other vertebrate remains from the Bostobynskaya formation, Northeastern Aral Sea region, Republic of Kazakhstan. Cretaceous Research 25, 669-674.

Gauthier, J. 1986. Saurischian monophyly and the origin of birds. Memoirs of the California Academy of Science 8, 1-55.

Mayr, G. 2009. Paleogene Fossil Birds. Springer, Berlin.

Naish, D., Dyke, G., Cau, A., Escuillié, F. & Godefroit, P. 2011. A gigantic bird from the Upper Cretaceous of Central Asia. Biology Letters doi: 10.1098/rsbl.2011.0683

O’Connor, J., Chiappe, L. M. & Bell, A. 2011 Premodern birds: avian divergences in the Mesozoic. In Dyke, G. J. & Kaiser, G. (eds) Living Dinosaurs: the Evolutionary History of Modern Birds. Wiley Blackwell (London), pp. 39-114.

Taylor, M. P. & Naish, D. 2007. An unusual new neosauropod dinosaur from the Lower Cretaceous Hastings Beds Group of East Sussex, England. Palaeontology 50, 1547-1564.

Xu, X., You, H., Du, K. & Han, F. 2011. An Archaeopteryx-like theropod from China and the origin of Avialae. Nature 475, 465-470.

Darren Naish About the Author: Darren Naish is a science writer, technical editor and palaeozoologist (affiliated with the University of Southampton, UK). He mostly works on Cretaceous dinosaurs and pterosaurs but has an avid interest in all things tetrapod. His publications can be downloaded at darrennaish.wordpress.com. He has been blogging at Tetrapod Zoology since 2006. Check out the Tet Zoo podcast at tetzoo.com!

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The views expressed are those of the author and are not necessarily those of Scientific American.





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  1. 1. pmurphy98 9:58 pm 08/9/2011

    Very interesting stuff Darren, as per the usual.
    Is it me, or does the human silhouette comparing the Samrukia and “normal-sized” mesozoic bird kind of look like Michelangelo’s David? Probably just me.

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  2. 2. Pristichampsus 11:22 pm 08/9/2011

    Isn’t it at least remotely plausible that it was heavy AND flighted, like a bustard or stork?

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  3. 3. pilsator 2:53 am 08/10/2011

    Congrats for naming this new taxon, Darren!

    I love it when something new goes to show just how patchy the current fossil record is. It’s not like “something” or “most” is unknown, it’s that almost nothing is known. And I do love the apparent “aberrantness” of such newly-described taxa. Limusaurus rocked my world for the sake of its ridiculous autapomorphicness, not the very debatable frameshift hypothesis (getting hot news again after Towers et al., 2011).

    Just skipped over to Theropoda. So your phylogenetic analysis is part of Andrea Cau’s megamatrix? Great to see an excerpt of it published :)

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  4. 4. Therizinosaurus 4:51 am 08/10/2011

    Congratulations!

    “given the fondness blog readers have for pickiness”

    That’s my cue! Technically, your consensus tree doesn’t exclude Archaeopteryx from Avialae. You’d have to look at the source trees to tell, but the published tree is consistant with any combination of deinonychosaurs, scansoriopterygids, Archaeopteryx and birds. It’s even possible Archaeopteryx is an avialan in every tree, but scansoriopterygids are sometimes closer to more derived birds, and sometimes deinonychosaurs and/or basal paravians.

    “I won’t bore you with details of the long, tedious, pre-publication history of this paper”

    I’d find such things incredibly interesting.

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  5. 5. BrianL 5:49 am 08/10/2011

    This is very interesting indeed! It once again shows how little we really know about Mesozoic birds (and,perhaps, makes me slightly less sceptical of the hypothesis that the neornithean radiation was well underway in the late Cretaceous). It’s not as tantalising as knowing the sole zygodactylous Mesozoic bird bird from just footprints, though. What on earth could that mysterious ‘roadrunner’ have been?

    Speaking of tantalising, I’d expected this ‘big post on wednesday’ to be about that ‘neornithean holy grail’ I saw you twittering about. Can I ask you what that was about?

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  6. 6. Symbiartic.km 11:29 am 08/10/2011

    So cool! But rrrgggg, the fossil record can be tantalizing… I want more of this beast!

    Also wanted to note that your post is beautifully illustrated, as always. Props!

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  7. 7. David Marjanović 1:24 pm 08/10/2011

    Jeholornis prima

    J. primus. Article thirty-something of the ICZN is unambiguous: the original form is wrong, and the corrected form must be attributed to the original authors.

    Interesting that Megamatrice finds Shenzhouraptor, Jeholornis and Jixiangornis as distinct. How many differences are there, and to which extent can we trust the descriptions?

    Avialae, in my opinion, is superior since it should be understood – right from its earliest use (Gauthier 1986, p. 36) – to be maximally inclusive

    Well, Gauthier redefined it twice: once as node-based (Archaeopteryx + Neornithes) and once (with de Queiroz, 2001) as apomorphy based (first animal with flight-enabling wings homologous to those in some extant bird, plus all its descendants… I should actually look up the exact wording). The node-based definition seems to enjoy fairly widespread use.

    Do you want to restrict Aves to the crown? Or do you want it to be dropped altogether?

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  8. 8. John Conway 3:45 pm 08/10/2011

    @pmurphy98

    Yes, it is indeed Michelangelo’s David! I’m worried nobody got that, and thought I just drew some random homoerotic nude dude.

    Cool to see this out Darren!

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  9. 9. Jerzy New 4:13 pm 08/10/2011

    I wonder if Samrukia could be moderate bird with outsized bill, like a pelican.

    About Archeopteryx/birds, I thought very definition of birds includes descendants of last common ancestor od Archeopteryx and sparrow. So deinonychosaurids become flightless (or never flighted) birds.

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  10. 10. Jerzy New 4:18 pm 08/10/2011

    Other question is what food is implicated by this ramii? It could point at the size and apperance of Samrukia.

    Could it be a smallish pelican, or giant, perhaps eagle sized, kingfisher analogue, or a goose-sized shoveler duck?

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  11. 11. neovenator250 5:59 pm 08/10/2011

    This is pretty cool! Anyone know where I can read more about this faunal community?

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  12. 12. neovenator250 7:49 pm 08/10/2011

    especially the tyrannosaurs and any crocs

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  13. 13. naishd 8:59 pm 08/10/2011

    Thanks much for comments, everyone. Sigh… never thought I’d regard 12 comments as “a lot”. Anyway…

    Pmurphy98: the identity of the human silhouette is – I would hope – so obvious that I thought we could all get away without mentioning it. But, yes, you’re right (as John says in comment 8).

    Pristichampsus: a variety of body shapes is possible so, yes, it could have been a really big, heavy-bodied flier (giant teratorn Argentavis is estimated to have weighed more than 70 kg).

    BrianL: that ‘neornithine holy grail’ is something I can’t talk about yet. As usual, I’m hyperbolising somewhat, but you’ll find out in time… And, yes, that zygodactyl Mesozoic track is very cool.

    David Marjanović: I’ve mostly been thinking that a branch-based Avialae (as per Gauthier’s original usage) is best, and I’d like to ignore the node-based and poor apomorphy-based definitions he proposed later on. But I could be persuaded otherwise – I still think that ‘majority usage’ is an important thing to keep in mind when formulating definitions, and it’s true that the majority of scientists/biologists/palaeontologists include Confuciusornis, enantiornithines and so on in their concept of Aves. But my general feeling is that the ambiguity that concerns the term Aves means that it might not be a bad idea to ignore it – we have Avialae for the whole branch and Neornithes for the crown.

    Jerzy: with only a partial lower jaw to go on, we can only speculate about the appearance of this bird. Yes, I suppose it’s possible that it was built like a toucan, pelican, big-billed kingfisher or shoveler duck, but that would be weird in view of what the body shapes were like in the other birds in this part of the tree. In other words, more ‘normal’ proportions should be expected until better evidence indicates otherwise. We’ve been careful throughout our writings on Samrukia to emphasise that we don’t know enough to say anything with confidence. And there’s no evidence from the mandible what Samrukia did for a living – as I’ve said, it might have been a generalist/omnivore of some sort, but this is totally speculative.

    neovenator250: for more on the fauna, see the Averianov and Dyke & Malakhov papers cited above for starters. Sorry, I’m sure that’s not much help if you don’t have access to the literature.

    Darren

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  14. 14. Dartian 2:56 am 08/11/2011

    Congratulations, Darren (et al.)! Who came up with the name?

    As for comparing Samrukia to a human figure shaped after Michelangelo’s David: I wonder how many people who see that image will fail to notice that it’s not supposed to represent the actual statue and thus be led to believe that Samrukia was over 5 metres tall..? ;)

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  15. 15. David Marjanović 8:46 am 08/11/2011

    The DOI still doesn’t exist, Biology Letters doesn’t do early-view articles, and the paper isn’t in the issue for August 23rd, the current one. :-( How did the media even learn of it?

    And I’m not on Twitter; I don’t see your tweets except when they happen to show up in the feed on the main page. Did you say anything about the holy grail other than its existence? :-)

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  16. 16. naishd 9:14 am 08/11/2011

    The Royal Society puts out press releases on a Wednesday, at 00-01 BST. Prior to today, I assumed that this was is also the time at which the digital ‘in press’ version of the respective publication is also released but, yes, you’re right – that ain’t so, and the paper is not yet out. I had no idea this is how things work at the Royal Society – given that it could screw with the publication of new taxa, it’s not a satisfactory situation.

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  17. 17. naishd 9:16 am 08/11/2011

    Oh, and – Dartian – Pascal came up with the name.

    Interesting stuff has emerged today concerning Samrukia. We _will_ be coming back to it in time!

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  18. 18. Yodelling Cyclist 1:16 pm 08/11/2011

    I must open with a disclaimer – I’m a chemist, and am merely Wikipedia-deep on this subject area.

    Secondly this is marginally off-topic, but anyway.

    What does the grouping of Archeopteryx with the deinonychosaurs indicate regarding the hypothesis that Deinonychus itself and its ilk were secondarily flightless? Is it at all plausible (given the apparent profusion of small therapods with pennacious feathers) that flight evolved repeatedly amongst these animals?

    Anyway, best wishes, congratulations to the author, and thanks in advance for any thoughts on the above questions.

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  19. 19. Halbred 2:15 pm 08/11/2011

    Finally bit the bullet and registered with Sci.Am. just for my favorite blog. :-)

    Darren, congrats on the new bird. I’m loving the idea of a big, possibly carnivorous ground bird snorfing down baby dinosaurs.

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  20. 20. John Harshman 3:43 pm 08/11/2011

    Count me as a supporter of crown group Aves and use of Avialae for the most popular alternative clade. Crown group definitions for all extant groups, that’s my dream.

    And doesn’t use of David as your human figure encourage everyone to think that Samrukia is much bigger than you want to claim? I make it about 6.5 meters tall in your reconstruction.

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  21. 21. Jerzy New 4:31 pm 08/11/2011

    Darren congratulations!
    You also made it to BBC news
    http://www.bbc.co.uk/news/science-environment-14466814

    Link to this
  22. 22. Yodelling Cyclist 6:34 pm 08/11/2011

    So this is an avian Goliath?

    Link to this
  23. 23. Heteromeles 6:35 pm 08/11/2011

    Neat stuff!

    I’m still trying to picture it as flightless, and somehow, that doesn’t work for me. Compared to the carnivores of the time, it’s a smallish bird, and somehow, that doesn’t sound like a good recipe for flightlessness, unless it’s an incredibly fast runner.

    Link to this
  24. 24. Tamara Henson 7:34 pm 08/11/2011

    I’ve never acknowledged Avialae as ever since it was proposed it had the same definition as traditional Aves (AKA: Archaeopteyx + Modern Birds)and Avialae seemed a little redundant. We need less junior synonyms not more and the crown clade already has a perfectly good name – Neornithes.

    Personally I would be happy if dromaeosaurs end up as basal Aves, so what if Jurassic Park got it wrong. To me traditional Aves is older than deinonychosauria by decades and has priority. On the other hand I wish Reptilia had gone in the scrap basket with Pises and Vermes instead of being redefined.

    Link to this
  25. 25. Heteromeles 8:20 pm 08/11/2011

    While I realize that this is a zoology blog, just try explaining what happened to dicots and monocots. Or puffballs and truffles. It’s easier for vertebrates, trust me.

    Besides, if feathers don’t define birds, what are you going to say next? Hair and mammaries doesn’t define mammals? We’re one good fossil away from that, too.

    Link to this
  26. 26. victorg 9:37 pm 08/11/2011

    Congrats on the new paper and description, Darren :)

    OT: It’s nice to see some old timers popping up here, the comments start to look TetZoo-like again. But I’m afraid it could lead to us getting used to fewer comments from fewer people: some very informative and/or interesting comments in v2 came from non-regulars.

    Link to this
  27. 27. John Harshman 1:00 am 08/12/2011

    Hair and mammaries don’t define mammals. Mammalia is a crown group, the common ancestor of monotremes, marsupials, and eutherians and all its descendants. Morganucodon isn’t a mammal. Neither are (if I remember) multituberculates.

    Link to this
  28. 28. Dartian 5:51 am 08/12/2011

    John: “Crown group definitions for all extant groups

    While that idea sounds reasonable in theory, I think it’s pretty much a non-starter in practice – at least when we’re dealing with such extant groups that have a substantial fossil record. Crown group definitions might perhaps not upset traditional ornithological classification all that much, but in mammalogy, using crown group definitions would mean that (for example) Thylacosmilus is not a marsupial, mastodons are not proboscideans, Elasmotherium is not a rhinoceros, Adapis is not a primate, Basilosaurus is not a cetacean, Smilodon and other various sabre-toothed tigers are not felids, Pliohippus and Hipparion are not equids, and so on, and so on. Strict crown definition usage would upset traditional mammal taxonomy so greatly that I simply can’t see it being accepted by most mammalogists any time soon.

    “Morganucodon isn’t a mammal

    It is, if we decide that it is.

    (As for multituberculates: the jury is still out regarding their exact phylogenetic placement, but recent analyses tend to find them as the sister taxon of Theria.)

    Link to this
  29. 29. David Marjanović 7:09 am 08/12/2011

    There are very few traditional mammals that aren’t crown-group mammals. Most or all people who work on them have now accepted the crown-group definition; the names Mammaliformes and Mammalimorpha already designate two slightly larger clades, and the crown-group doesn’t have another name! With birds, all this is different.

    And yes, don’t say Reptilia when you can say Sauropsida instead, which is pretty much always.

    …But back to the topic. :-) The paper is out!!! (Of course, it’s still “online before print”, though, so the name Samrukia still isn’t technically valid.)

    Link to this
  30. 30. Heteromeles 11:53 am 08/12/2011

    Um, crown groups? That’s a questionable way to do cladistics. There’s always this problem in assuming that extinctions prune branches on the edge of the tree, not in the middle of the tree. Dartian said it better than I did.

    All I’ll say is that everyone needs to remember these debates about taxonomic groups are now taking place in the open, on an international website where the users of taxonomic names and the general public are watching. When some phylogeneticist’s quest for perfection interferes with little things like enforcing CITES, maintaining endangered species regulations (something I just saw last week, where a threatened species was split into two species, one of which the USFWS didn’t want to list as threatened), or simply turns off budding paleontologists and biologists, it causes problems.

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  31. 31. John Harshman 4:00 pm 08/12/2011

    Whatever are “the edge of the tree” and “the middle of the tree”?

    I’m willing to make an exception for crown group names if they would result in too many synonyms. If, for example, strict enforcement would render Elephantidae and Proboscidea synonymous, then it makes sense for only the latter to have a crown group definition. I see no major reason to be worried about whether mastodons do or don’t belong to either. Names are just names.

    Accusing phylogeneticists of endangering species by splitting them is just plain weird. If you’re going to view with alarm, back it up with something better.

    Link to this
  32. 32. John Harshman 4:14 pm 08/12/2011

    “…it makes sense for only the former to have a crown group definition”, I mean.

    Link to this
  33. 33. naishd 5:13 pm 08/12/2011

    One minor point WRT comment 28: at least some metatherian specialists already restricted Marsupialia to the metatherian crown… thus Thylacosmilus and other borhyaenoids are not marsupials… according to this view. Discussed here on Tet Zoo ver 2.

    Link to this
  34. 34. Heteromeles 5:40 pm 08/12/2011

    The splitting species issue is a real one, and it’s one I certainly hope won’t spread beyond this one pair of species.

    The bigger point that needs to be beaten into certain phylogeneticists’ heads is that taxonomy has real world consequences. I know some very tired volunteers who have to deal with those consequences, from rebuilding lists of sensitive species (so that agencies will protect them after their names change) to yes, spending far too long attempting to convince apparently clueless bureaucrats that, when a threatened species is split due to honest research, both species deserve threatened status, not just the one that retains the original name.

    These volunteers may not have a relevant PhD that satisfies your lofty standards of expertise, but they happen to care about species researchers use, and they spend more time than you do keeping track of them.

    Right now, I’m hoping that more phylogeneticists will begin to feel some moral imperative for dealing with the consequences of their research. At the very least, familiarize yourself with the conservation status of your species, understand how your work might affect the way they are seen legally, and do some minimal activism to make sure your work doesn’t lead to them being harmed. A letter expressing your concerns about legal status is quite appropriate, especially since the bureaucracies consider you to be an expert on the taxa you work on.

    If this is too much for you, stick to fossils.

    Link to this
  35. 35. John Harshman 7:03 pm 08/12/2011

    Heteromeles: if you’re interested in something other than just being sanctimonious, please explain further. First, does this have anything whatsoever to do with crown group definitions? Second, are you proposing that no species should be split? Or if not, what are you proposing? What are systematists doing that’s pernicious?

    Also, please explain what you meant by “the edge of the tree” and “the middle of the tree”.

    Link to this
  36. 36. David Marjanović 11:00 am 08/13/2011

    Um, crown groups? That’s a questionable way to do cladistics.

    It’s not a way to do cladistics (phylogenetics) at all. It’s nomenclature.

    Phylogenetics is science. Nomenclature is about where on the tree to tie which labels.

    BTW, I don’t understand either what “edge” and “middle” of a tree are.

    Link to this
  37. 37. Mike from Ottawa 2:20 pm 08/14/2011

    “Samrukia nessovi was born. … the specific name honours the contribution to Central Asian vertebrate palaeontology of the late Lev Nessov (1947-1995).”

    Did you have a twinge about the specific name after you saw the Telegraph article?

    In thinking about the height, if flightless, did you consider it might only be 1 meter or less high even with such a long jaw if Samrukia were a member of the Disneyornithidae?

    Link to this
  38. 38. Heteromeles 8:50 pm 08/14/2011

    I’m not proposing no species be split. I’m just making the point, repeatedly, that naming has consequences. In this particular botanical situation (it’s up in the air, so sorry, I’m not providing details), AFAIK, the people who did the splitting are not part of the group of volunteers who are trying to make sure that the new species also gets threatened status, and does not have its populations opened to development (they were protected as critical habitat under the old name).

    I find it sad that saying that species definitions have conservation consequences appears sanctimonious.

    As for branches on the edge vs. the center, pretend that a cladogram is a tree, say with 10 branches, no reticulation. Typically, allopatric speciation does not happen to the basal-most clade. that would be easy to split into two clades. More often, populations on one of the more derived branches undergo speciation, perhaps radically (cf hawaiian tarplants). That’s within the crown. The problem is that strict cladists will then split the cladogram into a bunch of new clades, and it’s not necessarily useful.

    Here’s the silly example to make the point: Assume that, 20,000 years ago, aliens came to Earth and kidnapped a heterogenous sampling of African humans, for a breeding colony on Gliese 581 D. Since Gliese 581 is a red dwarf, that breeding colony has been under intense selective pressure for the last 20,000 years. As a result, they are no longer human, in the sense that they couldn’t interbreed with us if the aliens reunited us. Under this scenario, humans are not a species, and furthermore, we are multiple, independent clades. Even though we don’t know the kidnapping happened. As I said, it’s a deliberately stupid example. However, these type of “splitting the crown” decisions happen all the time when naming clades.

    Unfortunately, the decisions are not just academic. They affect conservation and preservation efforts. This can range from papers on conservation biology being hidden by obscure/poorly accepted name changes (a real problem in bats, where each state in the southwest US maintains a different set of names for some Myotis species), to screwing up species lists for habitat restoration, to problems like the species split I mentioned above.

    The point is not to stop doing this, it’s to pay attention to the consequences of your phylogenetic work. Please please help everyone else who uses your information to cope with the changes you propose. This includes speaking up about conservation issues that affect particular species, annotating specimens, communicating with conservation services where your organisms occur (especially if they are rare), talking to conservation and preservation volunteer groups, and so on. Think of this as a simple quid pro quo, to insure that you and your students still have living organisms to study in the decades to come.

    Link to this
  39. 39. Jenny Islander 11:23 pm 08/14/2011

    Heigh-ho, I finally signed on!

    Apropos of trying to figure out how big fossil birds were, I’m trying to find more info on “a gigantic gooselike anatid from O’ahu.” Besides the quoted text, which is repeated all over the place, I can only gather that the fossil remains are “extremely fragmentary.” Has this thing been described? Named? Is there a tentative reconstruction with possible numbers, anything more precise than “gigantic?” Anybody know?

    Link to this
  40. 40. Dartian 3:51 am 08/15/2011

    David: “There are very few traditional mammals that aren’t crown-group mammals.

    But these (probably) include such famous taxa as Castorocauda and Repenomamus. And yes, Morganucodon too; as fossil organisms go, it may not have the same superstar status as, say, Archaeopteryx, but it’s not entirely obscure either. (Besides, the current phylogenetic position of Multituberculata is by no means set in stone.)

    John: “Names are just names.

    Maybe so, but an awful lot of biologists certainly do seem to be making an awul lot of fuss about them…

    Darren: “some metatherian specialists already restricted Marsupialia to the metatherian crown… thus Thylacosmilus and other borhyaenoids are not marsupials

    I know that some people are doing that – and I disagree with that. Thylacosmilus is an iconic and widely known taxon. It’s a classic textbook example of convergent evolution (and whenever it is mentioned in such a context it is always referred to as a ‘marsupial’). Including Thylacosmilus in Marsupialia wouldn’t make the latter taxon either poly- or paraphyletic, so I can see no compelling phylogenetic reasons against its inclusion either. To place Thylacosmilus in Metatheria rather than in Marsupialia is not a satisfactory solution (and borders on a cop-out), because when people say ‘metatherian’, they virtually always mean ‘marsupial’ in the traditional, pre-phylogenetic-nomenclature-era sense. IMO, any definition of Marsupialia that doesn’t include Thylacosmilus is a bad definition of Marsupialia and should therefore not be endorsed.

    (Speaking of Metatheria: I’m in favour of retiring that name altogether, precisely because it’s mostly just used as a synonym of Marsupialia anyway. And while I’m at it, for similar reasons I’m in favour of officially abandoning Prototheria (which is quite rarely used nowadays) and Eutheria too. Replace them with Monotremata and Placentalia, respectively.)

    Link to this
  41. 41. John Harshman 9:08 am 08/15/2011

    I find it sad that saying that species definitions have conservation consequences appears sanctimonious.

    That sentence appears exceedingly sanctimonious. Just so you know. It appears that you are injecting a personally important but irrelevant controversy into a discussion of something else entirely. Whether a Cretaceous fossil is included in Aves or left out can have no bearing on conservation biology, nor can any discussion of crown group definitions. I would like to point out that no change to a crown group definition can possibly affect any living species, by definition.

    Nor is there any “basal” member of a clade, or any sort of “edge” or “center”. What you mean, apparently, is that speciation tends to happen in the most speciose part of a clade, which makes perfect sense even if every species has an equal chance of speciating. But this doesn’t mean the clade has to be split. And if we’re talking about a single species only, there’s no requirement that species be monophyletic, at least under the biological species concept. In your silly example, a new species emerges within H. sapiens, but H. sapiens just goes on, minus one population. There are examples of such things on earth.

    Now it’s true that species can be split and lumped for all sorts of reasons. In the extremely rare situation in which this affects conservation decisions, it might be incumbent on the lumper/splitter to explain the facts to government officials, but it seems much more incumbent on those government officials to understand the science, and not interpret regulations so as to prevent the tracking of simple name changes.

    Link to this
  42. 42. Heteromeles 4:04 pm 08/15/2011

    Now it’s true that species can be split and lumped for all sorts of reasons. In the extremely rare situation in which this affects conservation decisions, it might be incumbent on the lumper/splitter to explain the facts to government officials, but it seems much more incumbent on those government officials to understand the science, and not interpret regulations so as to prevent the tracking of simple name changes.

    Yes, this was an interjection. No, the phenomenon is not rare. I’ve dealt directly or indirectly with three of those issues in my county (not country, COUNTY) this year.

    It’s not cheap either. The bat issue I alluded to (where every state uses a slightly different set of names) set a local agency back something like $4,000 of my time in research, while I tried to help them come up with a bat conservation plan.

    So yes, your phylogenetic actions have consequences.

    Link to this
  43. 43. David Marjanović 5:16 pm 08/15/2011

    Here’s the silly example to make the point: Assume that, 20,000 years ago, aliens came to Earth and kidnapped a heterogenous sampling of African humans, for a breeding colony on Gliese 581 D. Since Gliese 581 is a red dwarf, that breeding colony has been under intense selective pressure for the last 20,000 years. As a result, they are no longer human, in the sense that they couldn’t interbreed with us if the aliens reunited us. Under this scenario, humans are not a species, and furthermore, we are multiple, independent clades. Even though we don’t know the kidnapping happened. As I said, it’s a deliberately stupid example. However, these type of “splitting the crown” decisions happen all the time when naming clades.

    Here you’re confusing “clade” and “species”.

    As of February 2009, there are 147 different species concepts. When applied, each of them leads to different results. Under some of these concepts, species are automatically clades, so the scenario you explain is possible (and no ancestor can ever be referred to a species); under the others, species are allowed to be paraphyletic.

    Link to this
  44. 44. David Marjanović 5:31 pm 08/15/2011

    I didn’t mean to send this yet… the cursor just disappeared…
    Something else that’s very important: you keep using the term “crown group”. I do not think it means what you think it means.
    The crown-group of a clade is the most recent common ancestor of all extant members of the clade, plus all descendants of that ancestor.

    Apropos of trying to figure out how big fossil birds were, I’m trying to find more info on “a gigantic gooselike anatid from O’ahu.”

    Google for “moa-nalo”. I think that’s it.

    David: “There are very few traditional mammals that aren’t crown-group mammals.”

    *howl* We can’t do nested quotes here! What kind of science blog platform is this!!!

    But these (probably) include such famous taxa as Castorocauda and Repenomamus. And yes, Morganucodon too

    Morganucodon and Castorocauda, yes. The triconodont Repenomamus, probably not, though that’s no safer than the position of the multituberculates.

    (Speaking of Metatheria: I’m in favour of retiring that name altogether, precisely because it’s mostly just used as a synonym of Marsupialia anyway. And while I’m at it, for similar reasons I’m in favour of officially abandoning Prototheria (which is quite rarely used nowadays) and Eutheria too. Replace them with Monotremata and Placentalia, respectively.)

    There is no way to officially abandon such a name, because the ICZN simply ends at the superfamily level*. But anyway, Prototheria hasn’t been used in the primary or secondary literature in decades. However, Metatheria and Marsupialia, and Eutheria and Placentalia, are pretty firmly entrenched as pairs of a total group and its crown group. The times when they were used as synonyms are over. Even the few holdouts who do not restrict Marsupialia and Placentalia to the crown-group do not equate them with their total groups; in 1997 there was a paper that showed Deltatheridium is a metathere and used the name Marsupialia for everything closer to the crown than to Deltatheridium.
    The total group of an extant clade consists of everything more closely related to that clade (obviously this includes itself) than to any other extant organisms. This allows Metatheria and Eutheria to be sister-groups by definition.

    * It regulates names at the species group, genus group and family group of ranks. Beyond that, it only regulates the uttermost basics like which alphabet to use; even priority explicitly does not apply.

    Nor is there any “basal” member of a clade, or any sort of “edge” or “center”. What you mean, apparently, is that speciation tends to happen in the most speciose part of a clade, which makes perfect sense even if every species has an equal chance of speciating.

    Bingo. The way Heteromeles uses “basal” is tautological.

    So yes, your phylogenetic actions have consequences.

    None of us here, I think, works on alpha taxonomy of extant organisms.

    Link to this
  45. 45. John Harshman 6:15 pm 08/15/2011

    Heteromeles:

    So you’re complaining about something that’s completely irrelevant to this thread and to the work of almost everyone who comments here, merely because it’s one of your personal obsessions. Hey, your comments have consequences, and that makes me sad.

    Not only are you talking to the wrong people, you are confusing phylogenetics with alpha taxonomy. But it seems to me your main complaint should not be addressed even to alpha taxonomists but to the silly government officials who can’t see past the names to the things being named.

    Link to this
  46. 46. Heteromeles 6:39 pm 08/15/2011

    No, actually I’m not confusing alpha taxonomy with phylogenetics. I’m marginally better educated than that (and I’ve taught systematics).

    Currently, I deal with the consequences, working as part of a group that not only lobbies for conservation, but supports conservation, invasive species control, rare species monitoring (my current assignment), and phylogenetic research. I’m also on the panel that reviews academic grant applications, too.

    That said, you’re right, this is the wrong audience. My apologies for disturbing you. Please continue discussing fossils.

    Link to this
  47. 47. John Harshman 7:07 pm 08/15/2011

    I am willing to believe you. But species splitting is most definitely not phylogenetics, so be aware that your statements have been considerably at variance with your intentions. You have given no examples in which phylogenetics has any consequences for conservation biology. Now I can see that moving a species into a new genus, which may be required by a phylogenetic analysis, might have consequences given ignorance on the part of government officials. But that still seems to be the fault of the government official and not something you should be criticizing scientists for. And by the way, just so you know, you’re still sounding highly sanctimonious.

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  48. 48. Halbred 7:32 pm 08/15/2011

    Heteromeles said: “That said, you’re right, this is the wrong audience. My apologies for disturbing you. Please continue discussing fossils.”

    We will, thanks. I believe fossils are the subject of this very post!

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  49. 49. Dartian 5:19 am 08/16/2011

    David: “What kind of science blog platform is this!!!

    Antediluvian.

    There is no way to officially abandon such a name

    I suspected that was the case. But I can dream, can’t I?

    the ICZN simply ends at the superfamily level

    What does that not-yet-officially-launched biological nomenclatural system (you know which one I mean) say about about these kinds of issues?

    As for the respective definitions of Metatheria & Marsupialia; I would personally favour a definition of Marsupialia that includes all the metatherians present in South America by the time it separated from Laurasia and Africa (in the Late Cretaceous?) and all their descendants. Thus, Deltatheridium and other Laurasian (and African?) metatherians would be outside Marsupialia, whereas Thylacosmilus, borhyaenids, argyrolagids, and other extinct and extant South American taxa (as well as all those in Antarctica and Australasia) would be inside it. And everyone would be happy… :)

    * There is, of course, the theoretical possibility that post-breakup South America was colonised more than once by metatherian lineages from the north; this would slightly complicate matters. But AFAIK there is currently no good evidence for such multiple invasions by metatherians.

    None of us here, I think, works on alpha taxonomy of extant organisms.

    Do you mean this particular discussion thread, or Tet Zoo commenters in general?

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  50. 50. David Marjanović 7:23 am 08/16/2011

    species splitting is most definitely not phylogenetics

    Under some species concepts it is…

    moving a species into a new genus, which may be
    required by a phylogenetic analysis

    if we insist that genera be monophyletic, which more and more people do, but the ICZN still doesn’t.

    What does that not-yet-officially-launched biological nomenclatural system (you know which one I mean) say about about these kinds of issues?

    Under that system, priority will only start with that launch. Apart from that, it (recently) emphasizes continuity with “historical usage”, but it doesn’t give details.

    Do you mean this particular discussion thread, or Tet Zoo commenters in general?

    This particular thread. And of course I don’t actually know what some of the pseudonymous commenters do all day long…

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  51. 51. David Marjanović 7:24 am 08/16/2011

    Oh, I forgot: Marsupialia sensu Dartian already has a name — Notometatheria.

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  52. 52. Dartian 10:13 am 08/16/2011

    Marsupialia sensu Dartian already has a name — Notometatheria.

    I should have been aware of that, but I wasn’t. Thanks for the information!

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  53. 53. John Harshman 10:40 am 08/16/2011

    David: Under what species concept is species splitting a phylogenetic matter? I can’t immediately think of a version of the phylogenetic species concept under which this is true. Under one version of the PSC, a species is a diagnosable cluster, but a diagnostic character can easily be a plesiomorphy. I don’t know of a concept under which mutual monophyly is either necessary or sufficient.

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  54. 54. David Černý 3:57 pm 08/16/2011

    Hello from a first-time commenter!

    John Harshman wrote:

    Under what species concept is species splitting a phylogenetic matter?

    The phylogenetic species concept of Mishler & Donoghue (1982) or Mishler & Brandon (1987):

    “A species is the least inclusive taxon recognized in a classification, into which organisms are grouped because of evidence of monophyly (usually, but not restricted to, the presence of synapomorphies), that is ranked as a species because it is the smallest “important” lineage deemed worthy of formal recognition, where “important” refers to the action of those processes that are dominant in producing and maintaining lineages in a particular case.”

    (Mishler & Brandon 1987: 406)

    “The definition of monophyly given above solves the problem [...] with “ancestral species.” No such things exist. Only parts of an original species give rise to new ones, as in the above examples. If a currently recognized species is found to be paraphyletic because parts of it can be demonstrated to be more closely related to another species [...], then the paraphyletic species should be broken up into smaller monophyletic species.”

    (Mishler & Brandon 1987: 410)

    Rosen (1979) argued for a strictly monophyletic species concept as well. In his view species should be the smallest clusters diagnosable by one or more autapomorphies (IIRC), while Cracraft, Nixon, Nelson, Wheeler, and Platnick require only a unique combination of characters.

    References:

    Mishler BD, Brandon RN 1987 Individuality, pluralism, and the Phylogenetic Species Concept. Biol Phil 2(4): 397—414

    Mishler BD, Donoghue MJ 1982 Species concepts: A case for pluralism. Syst Zool 31(4): 491—503

    Rosen DE 1979 Fishes from the uplands and intermontane basins of Guatemala: revisionary studies and comparative biogeography. Bull Am Mus Nat Hist 162: 267—376

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  55. 55. John Harshman 5:59 pm 08/16/2011

    Thanks. I had forgotten. I see the PSC mostly from the way it’s treated in Aves, more or less descending from Cracraft. The monophyletic PSC has big problems once you start looking at genetic data. There may, for example, be no monophyletic bits in the “ancestral” species, which is why the metaspecies idea was proposed. And there may be conflicting autapomorphies. But OK, there’s such a concept.

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  56. 56. pilsator 6:49 am 08/17/2011

    “The definition of monophyly given above solves the problem [...] with “ancestral species.” No such things exist. Only parts of an original species give rise to new ones, as in the above examples. If a currently recognized species is found to be paraphyletic because parts of it can be demonstrated to be more closely related to another species [...], then the paraphyletic species should be broken up into smaller monophyletic species.”

    Shouldn’t anagenesis be a problem here? If, say, species x would be a perfectly neat continuum to species y, with no discernible populations branching off into different “directions”, how could you leave it a monophyletic taxon if you apply the PSC to its descendants?

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  57. 57. John Harshman 10:45 am 08/17/2011

    Pretty much any species concept runs into problems if applied over evolutionary time scales. Deal with it. But anagenesis isn’t a problem for monophyly version of the PSC. No branching, no speciation, no species x or y, just species xy.

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  58. 58. David Černý 10:56 am 08/17/2011

    John Harshman wrote:

    There may, for example, be no monophyletic bits in the “ancestral” species, which is why the metaspecies idea was proposed.

    Interesting. Mishler and Brandon mentioned the concept of metaspecies in their paper. They used the term for “groups that are not known to be either paraphyletic or monophyletic” and considered it acceptable “as long as a special convention [is] followed to indicate the uncertain status of the species”. Gauthier (1986) followed such a convention: he marked the names of metaspecies (such as Archaeopteryx) with asterisk, just as Donoghue (1985) had originally suggested.

    (BTW, congratulations for having your 2008 hypothesis of ratite polyphyly further supported by Johnston’s morphological cladistic analysis!)

    pilsator wrote:

    Shouldn’t anagenesis be a problem here? If, say, species x would be a perfectly neat continuum to species y, with no discernible populations branching off into different “directions”, how could you leave it a monophyletic taxon if you apply the PSC to its descendants?

    I’m not completely sure I understand your question, but I think that the PSC (sensu Mishler and Brandon) would recognize only y as a species. The whole continuum from x to y could be a valid clade but not species, because it is possible to recognize a less inclusive inside it.

    References:

    Donoghue MJ 1985 A critique of the Biological Species Concept and recommendations for a phylogenetic alternative. Bryologist 88: 172-81

    Gauthier JA 1986 Saurischian monophyly and the origin of birds. Mem Calif Acad Sci 8: 1-55

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  59. 59. John Harshman 5:11 pm 08/17/2011

    BTW, congratulations for having your 2008 hypothesis of ratite polyphyly further supported by Johnston’s morphological cladistic analysis!

    Considering the number of molecular loci already supporting this (now upwards of 70, if I’m counting right, though most are still unpublished), no big deal. And I don’t have access so far, so I hope he cited Elzanowski 1995, which came to the same conclusion on the basis of cranial data, and I wonder what you have to do to make all this fit a strictly vicariant model.

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  60. 60. David Černý 7:03 pm 08/17/2011

    Considering the number of molecular loci already supporting this (now upwards of 70, if I’m counting right, though most are still unpublished)

    Wow! This makes Hackett et al. 2008 look pretty outdated. I forgot for a moment that the goal is nothing less than four million bases…

    And I don’t have access so far, so I hope he cited Elzanowski 1995 [...]

    Neither do I, unfortunately. However, the abstract says that the “new” topology resulted from the inclusion of “characters from the tongue apparatus and cranial osteology” — the same data sources used by Bock, Bühler, and Elżanowski when they first proposed the hypothesis in the ’90s. It would be strange if Johnston didn’t cite them.

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  61. 61. John Harshman 8:52 pm 08/17/2011

    I may have created some confusion. The 70+ loci are for paleognaths only, not for the whole Hackett et al. taxon sample. And the 4 million bases often cited are the Hackett et al. data set, which is about 4 million bases counting taxa x sites.

    I consider Elzanowski the true originator of this hypothesis. Bock & Buhler offered little explicit character support, and what they had was uninformative unless you make all sorts of polarity assumptions. Elzanowski, on the other hand, had a real character matrix.

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  62. 62. David Černý 5:52 pm 08/18/2011

    Thanks for the clarification.

    Link to this
  63. 63. CLB393 2:06 pm 09/2/2011

    Regarding Archaeopteryx being removed from the Avian family tree. It makes absolutely no sense. Why? Archaeopteryx wore flight feathers. Not proto-feathers, or advanced scales or what have you, but asymmetrical flight feathers nearly indistinguishable from modern birds. So, if you say Arhcaeopteryx is NOT a bird then you say we have convergent evolution of an entire different order, right down to the minute barbules. Wow! If this is the case then perhaps NO birds are related to dinosaurs, that any similiarities are just convergent evolution. See how ridiculous it becomes? MODERN FLIGHT FEATHERS DEFINE ARCHEAOPTERYX AS A BIRD.
    Anyway, this will all be cleared up when the cladisticians finally move the entire Deinonychosaur clan to its proper place – under Aves

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  64. 64. naishd 5:54 pm 09/3/2011

    With respect, I get the impression that you don’t know what you’re talking about. In recent years it’s been discovered that complex, vaned feathers (with barbs and probably barbules) are not unique to the avian lineage (the one that includes modern birds and whatever fossil taxa are closer to them than to deinonychosaurs) but originated deeper within Maniraptora. “Modern flight feathers” do not “define Archaeopteryx as a bird”: feathers of this form were also present in oviraptorosaurs and deinonychosaurs at least, and hence were inherited by birds from earlier maniraptorans.

    Darren

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  65. 65. Buffetaut 5:35 pm 09/5/2011

    Sorry to be a nuisance, but Samrukia clearly is not a bird. It is just a relatively large pterosaur. The type specimen does not show a single avian apomorphy. All the purported “autapomorphies” (except “large size”, which of course does not mean anything) are common pterosaur characters. See Wellnhofer, 1980, on Gosau pterosaurs and pterosaur jaw mechanics for details (it’s in German – a language every self-respecting palaeontologist should master, I think).

    Link to this

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