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Dissecting a crocodile

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


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Some considerable time ago – it was, I discover to my surprise, April 2010 – I was lucky enough to participate in the Great Crocodilian Dissection Event at the RVC (Royal Veterinary College, UK), planned by the mighty and benevolent Prof John Hutchinson. John actually received a job-lot of numerous crocodilian specimens and arranged to have a large number of them dissected and studied over a period of a couple of weeks. Just about every free citizen involved in archosaur research descended upon the RVC. I’ve never had the chance to dissect a crocodilian before and I learnt a lot; I meant to blog about the event shortly after it occurred, but other things got in the way and it ended up on the backburner.

Here, at long last, I aim to talk you through just a few edited highlights of a croc dissection. Some of the observations concerned are applicable to all crocodilians while others are peculiarities of Osteolaemus, the animal I helped dissect (I couldn’t get to the RVC in time to work on Black caiman Melanosuchus niger or Morelet’s crocodile Crocodylus moreletii, dammit). My thanks to John and also to Vivian Allen for leading the dissection.

Oh, in the intervening TWO YEARS since we did the dissection, John has even started his own blog, titled What’s In John’s Freezer? It’s required reading for any self-respecting frequenter of Tet Zoo. I’d add it to my blogroll, if only I had one that was of any use whatsoever.

Crocodilia, Crocodylia, Crocodyliformes, Crocodylomorpha – why most people remain confused

In recent years it has become better appreciated among the interested public that the crocodilian fossil record includes an impressive amount of morphological and behavioural diversity. These cartoons (from Naish 2001) depict some of that diversity. Top to bottom: stomatosuchid (l), metriorhynchid (r), sebecosuchian (l), sphenosuchian (r).

Firstly – a minor point on nomenclature. This sort of thing has to be discussed whenever crocodilians are. The group of archosaurs conventionally called crocodilians, and frequently termed Crocodilia in the textbooks (that is, living crocodiles, alligators, gharials and all their crocodile-like, alligator-like and gharial-like fossil relatives) is now most typically termed Crocodyliformes. That is, ‘crocodilians’ of tradition are now crocodyliforms (note that the last ‘e’ gets dropped when you convert a ‘-formes’ name to its vernacular version). Within Crocodyliformes, the crown-group (that is, the group that contains the living species and all descendants of their most recent common ancestor) is termed Crocodylia. So, Crocodylia is a clade within Crocodyliformes (Clark in Benton & Clark 1988, Norell et al. 1994, Salisbury & Willis 1996, Brochu 2003).

Crocodyliformes is part of a more inclusive group that also includes the crocodyliform-like sphenosuchians, and this larger clade is termed Crocodylomorpha. In turn, Crocodylomorpha is part of a major archosaur group informally termed the crocodile-branch or crocodile-group archosaurs, the best technical name for which is (unfortunately) Pseudosuchia (how I hate the fact that this name might win out over Crurotarsi, if certain phylogenetic definitions are followed).

Massively simplified cladogram of crocodilians and their relatives, with numerous lineages not shown. The affinities between "rauisuchians", aetosaurs and crocodylomorphs are shown here as being unresolved, but some studies find aetosaurs to be closer to crocodylomorphs than are other croc-group archosaurs. Other studies find at least some "rauisuchians" to be closer to crocodylomorphs than are other croc-group archosaurs. Within Crocodylomorpha, some studies find thalattosuchians to be further away from Crocodylia than is Notosuchia.

In view of the confusion that ensues whenever an attempt is made to explain the use and meaning of these names (I’ve had to do it several times), I believe that we should stick with what we have: the archosaurs that we imagine as ‘crocodilians’ are now crocodyliforms, and the crocodyliform crown-clade is Crocodylia. However, some workers aren’t happy with this and have argued that we should use Crocodylia in place of Crocodyliformes (Martin & Benton 2008). I can’t see that this does anything useful bar complicate an already confusing situation and I think that we should ignore this proposal. When talking to technical audiences, I tend to use crocodyliform, but I don’t see anything wrong with ‘crocodilian’ being used as a vernacular term for the clades Crocodyliformes or Crocodylomorpha.

The African dwarfs… yes, plural

Happy little Osteolaemus, photographed in captivity.

Anyway, the species under consideration here is Osteolaemus tetraspis, the tropical African crocodile most usually known as the African dwarf crocodile. Other common names include Broad-snouted crocodile and Black crocodile, and there are apparently people who call it the Rough-backed crocodile, Bony crocodile or African caiman. A supposedly distinct kind of African dwarf crocodile from the upper Congo River Basin, named Osteoblepharon osborni, was described in 1919. However, it later became relegated to the status of an Osteolaemus tetraspis subspecies, and there followed suggestions that even this subspecific recognition was unwarranted (e.g., Ross 2006).

More recently, morphological (Brochu 2007) and molecular data (McAliley et al. 2006, Eaton et al. 2009) have shown that Congo River Basin dwarf crocodiles can be reliably distinguished from those dwarf crocodiles known from further west. Furthermore, these differences are as significant as those separating uncontroversial species elsewhere in the crocodile tree. Accordingly, O. tetraspis and O. osborni are now recognised as distinct species by some authors.

Furthermore, Eaton et al. (2009) also found that the O. tetraspis population of Gabon and the adjacent countries was significant different from the dwarf crocodiles of more western countries, leading to the suggestion that these should be recognised as distinct species as well (Eaton et al. 2009, Eaton 2010). A formal taxonomy that reflects this discovery has yet to be published (so far as I know). As usual, we’ll get a difference of opinion here. Should we formally name distinct phylogenetic lineages, or do we go with the idea that lumping the lineages together is more practical and sensible?

Skulking Osteolaemus in captivity.

Total lengths of 1.8 m are on record for Osteolaemus and there are even reports of animals 2.3 m long, so perhaps it isn’t necessarily always the ‘dwarf’ we think it is. This is a crocodile often stated to be of strong terrestrial habits, sometimes reported far (as in, a few kilometres) from water. However, little good data has been collected and published on its habitat preferences and behaviour and, while it might be proficient on land, there are more reasons for thinking that it’s a specialised animal of shallow pools, streams and other flooded habitats in closed-canopy forests. It’s said to be less aggressive than other crocodiles (the term ‘docile’ has been used), and to be especially curious.

Ok, enough preamble, on with the anatomy…

Short snouts, ‘poke-through’ dentitions and big palpebrals

How could anyone not love that cute little face? Alas, poor little croc.

Let’s start with the head. Modern crocodilians are well known for having elongate, superficially tubular snouts where the rostrum is dorsoventrally flattened. This is known as the platyrostral shape, and if you want to know more about it and about what it might mean for crocodilian feeding behaviour, skull loading and so on, see Busbey (1995). However, modern crocs aren’t all like this. Osteolaemus and the dwarf caimans (Paleosuchus) have deeper, proportionally short rostra, and it’s sometimes a matter of opinion whether they’re classified as altirostral or oreinirostral, rather than as platyrostral. ‘Altirostral’ and ‘oreinirostral’ both describe the ‘tall-snouted’ condition where the rostrum is relatively steep-sided and, overall, narrower and more vaulted than it is in platyrostral crocodilians.

Note the rugose look to the upper eyelids. This is mostly due to the mobile palpebral bones they contain.

In Osteolaemus, the snout is something like 1.3 times longer than it is wide as its base: that’s proportionally shorter than even a subadult Crocodylus crocodile. However, Busbey’s (1995) graph shows the snout of Osteolaemus to be not far removed in morphospace from undisputed platyrostral forms like Alligator, so Osteolaemus cannot be regarded as at all on par with truly altirostral animals like sebecosuchians or pristichampsids (two especially neat fossil crocodilian groups) (Busbey 1995, Rossmann 2000). While on the subject of snouts, something that Osteolaemus never does (apparently) is ‘allow’ its premaxillary bones to be perforated by its mandibular dentition. Yes, as remarkable as it seems to us, in crocodilians of many species, some of the teeth in the anterior part of the lower jaw cause holes to form in the corresponding parts of the upper jaw; the end result being that the teeth poke through specially formed holes. This isn’t unique to crocodilians – among fossil tetrapods it’s especially well known for some temnospondyls and there are also hints of it in pliosaurs.

I mentioned a moment ago that a proportionally short snout like that of Osteolaemus is also present in the Paleosuchus caimans. In fact, Osteolaemus shares other skull features with other short-snouted crocodilians. Osteolaemus and Paleosuchus both have especially large palpebral bones occupying the upper parts of their eye sockets (these are formed from several distinct ossifications that fuse together as the animals mature). Furthermore, their supratemporal fenestrae are proportionally small and become smaller during ontogeny.

Are the two taxa (Osteolaemus and Paleosuchus) especially similar in ecology or behaviour? Both are relatively small crocodilians of tropical forest floors, both are strongly terrestrial in comparison with other living crocodilians, and both may eat more hard-shelled prey (like crabs and snails) than do other crocodilians. Elsewhere within crocodilians, this short-snouted morphology also evolved within the recently extinct mekosuchines (Brochu 2001). Were the species involved similar in ecology and behaviour to Osteolaemus and Paleosuchus as well? Readers with good memories should recall the one or two articles I published on ver 2 about Mekosuchus and related forms.

Tracing of an x-rayed Osteolaemus, from Ross & Mayer (1983). The dorsal shield stops above the shoulders and two pairs of relatively enormous scutes are located over the neck. Relevant for the neck wars: note that the neck is inclined upwards relative to the dorsal vertebral column. This is normal for alert crocs: the neck does not continue in a straight line from the dorsal part of the vertebral column. Click to enlarge.

Scutes, and some muscles

Crocodilians are well known for possessing dermal scutes, or osteoderms. In Osteolaemus, the nuchal shield (the field of scutes covering the dorsal surface of the neck) is separated from the dorsal shield (the field of scutes covering the animal’s back) by a band of skin. There are (usually) only four nuchal scutes, hence the specific name ‘tetraspis’. The dorsal shield (understood to contain all scutes on the back anterior to the sacrum) is formed by 17 transverse rows of vaguely squarish scutes; each row consists of 4-8 (but usually 6) scutes (Ross & Mayer 1983). Croc scutes are almost certainly multifunctional. They provide protection from predators, they play some role in sociosexual display, they contribute to the collection and transfer of solar heat, and they perhaps function as part of a self-carrying system in which muscles attached to both the ventral surfaces of the scutes and to the vertebrae help the animal fight gravity (Frey 1988, Salisbury & Frey 2000).

Nuchal shield of Osteolaemus, removed as single unit.

A neat thing about the scutes is that they’re not all flat. Those at the lateral edges of the nuchal and dorsal shields have distinct medial and lateral parts in many crocodilians, with longitudinal keels positioned at the junction between the two. This is especially obvious in the large nuchal scutes of Osteolaemus. As you remove the nuchal shield of an Osteolaemus, the four scutes remain attached as a single unit and form a sort of neat little inverted box. If this was flipped upside down, you could keep it on your desk and use it as a container for paper-clips and drawing pins.

Dorsal musculature of the neck, visible as the nuchal shield is removed. Neat, pink transversospinalis capitis muscles.

Having removed the scutes and accompanying epidermis, we got to see the transversospinalis capitis musculature that runs along the dorsal surface of the neck. This was both deep and narrow, and also extremely pink, but I don’t know if that means anything in particular. If you dissect closer to the posterior border of the head, you of course get to see the gigantic depressor mandibulae and pterygoideus muscles, both of which take up an impressive amount of space about the back of the lower jaw and quadrate. Actually, while I’m familiar with the appearance and relative size of these muscles in Crocodylus crocodiles, I don’t know what they look like in Osteolaemus and I didn’t get to find out in this particular dissection. Oh well, maybe next time.

The hindlimbs and tail

Over 20 different muscle heads can't be wrong. The extracted muscle being held by human fingers is the ilio-tibialis 3. The ilio-femoralis is visible (roughly corresponding to the form of the femur)... as are many other muscles.

Finally, some brief comments on the hindlimbs and tail. Crocodilians have crazy complex hindlimb muscles, and I got to see many of those during the dissection. On the outermost surface of the thigh, the large and bulky ilio-tibialis is located more anteriorly than the flexor-tibialis externus – the muscle that forms the posterior border to the thigh. The ilio-tibialis actually has three distinct segments, all of which are attached to the dorsal edge of the ilium and all of which merge somewhere in the knee region. They overlie the two heads of the ambiens (one head originates from just anterior to the acetabulum, the other from the base of the pubic bone), the ilio-femoralis, the different parts of the femora-tibialis and various other muscles.

There’s also the ilio-fibularis, sandwiched in between some of the ilio-tibialis components but emerging distinctly on the lateral surface of the knee. Here, this muscle runs through a weird ‘tendon sling’ attached to the side of the femur and gastrocnemius (Romer 1923). Of course, I’ve hardly mentioned most, let alone all, of the pelvic and hindlimb muscles here: there are as many as 23 different muscle heads crossing the pelvis in crocodilians, and the interplay between them “is extremely difficult to resolve” (Gatesy 1997, p. 208).

One of the most distinctive features of archosaurs is a prominent muscle attachment site on the posterolateral part of the femur. Known as the fourth trochanter, it’s the attachment site for the caudofemoralis longus (cfl for short) – a large muscle that also attaches to the sites of the caudal vertebrae and is involved in retracting the femur during locomotion. I’ve never dissected out a cfl before and wanted to see both how clearly differentiated it was from the adjacent caudal muscles, and also how far it extended along the tail.

A neat and tidy extraction of a cfl.

As you can see from the photo here, it is in fact pretty easy to dissect the cfl out separately from the adjacent, dorsally sited longissimus and the more ventrally sited ilio-ischiocaudalis and other tissues, so long as you’re careful. The cfl looks weird for a tail muscle – it isn’t ‘segmented’ into myosepta and hence looks more like a limb muscle than an axial one. I’m not an especially huge fan of eating meat, but I can certainly appreciate how people might look at the cfl and think “Wow, that archosaurian caudofemoralis longus sure like looks it would make a good fillet”. If you’ve been paying attention to the dinosaur literature you’ll know that long-tailed dinosaurs have, it turns out, long been reconstructed with inadequately sized cfls; there’s now a push to give dinosaurs thicker, more muscular tails (Hutchinson et al. 2011, Persons & Currie 2011).

There is a ton more that could be said – crocodilian pelvic and belly musculature, their respiratory anatomy, their amazing heart anatomy, their shoulder joints and jaw muscles have all been recent areas of substantial interest. But I have to move on. We’ll be coming back to crocodilians real soon.

And I also haven’t much covered the affinities of Osteolaemus with respect to other crocodilians. Work on fossil species seems to show that Osteolaemus is the only extant member of a once diverse clade that includes various small, mid-sized and large crocodylid crocodilians of Africa and the Indian Ocean. Some of these animals have been written about on Tet Zoo ver 2 – in view of what’s just happened to that site (read on), I don’t think it’s worth my while adding links anymore.

I should add that, well before the dissection started, the specimen was CT-scanned. Viv Allen (on left) promotes crocodilians to an interested party.

Two unconnected announcements

Two more things while I’m here. If you’ve been keeping an eye on the comments here at ver 3, you’ll have seen the discussion about changes just made to ver 2 (archived at ScienceBlogs). ScienceBlogs has just migrated to WordPress, meaning that Tet Zoo ver 2 now has a totally new look. As usual, things are not better than they were, but worse. The blogroll has totally gone, the formatting of the articles has been royally screwed with (annoyingly, all accented characters have been removed), and – most devastatingly – all the comments have gone. That’s a major loss. As regular readers will know, the (often substantial) comment threads attached to many of the articles included a huge amount of debate and accessory information. I’ve managed to get behind the scenes at WordPress, and I’m sorry to say that there’s no sign of the comments whatsoever – they seem to be totally gone. I know that there are ways of accessing old webpages (Wayback Machine and so on), and people tell me all the time how difficult it is to ever really remove anything from the web… nevertheless, this (at least superficial) loss is a major blow to the value and content of Tet Zoo. Seeing as I’m not with ScienceBlogs anymore, there’s nothing I can do, nor was I at all aware of these impending changes. Comments were open at Tet Zoo ver 2 yesterday but a huge flood of spam caused me to turn off commenting site-wide.

On to the second thing… Those of you interested in open access and in publishing ethics will know that some academic publishers have been doing their very best to prevent open access to publicly funded research. Yes, you read that right. They believe that the public should not be allowed to freely access the scientific literature it funds. A substantial amount of digital ink has been spilt on this matter in recent months, as you’ll know if you read SV-POW! or if you’re aware of the internet in general. One of the latest developments in this saga is that a petition organised by Whitehouse.gov is currently taking signatures to allow publicly-funded research to be openly available to the public, as of course it ethically should be. This will be presented to the Obama Administration. If you support open access, and if you believe (as I do) that publishing companies have no right to keep publicly-funded research behind paywalls, please sign now, and encourage others to do likewise.

Refs – -

Benton, M. J. & Clark, J. M. 1988. Archosaur phylogeny and the relationships of the Crocodylia. In Benton, M. J. (eds) The Phylogeny and Classification of the Tetrapods, Volume 1: Amphibians, Reptiles, Birds. Clarendon Press (Oxford), pp. 295-338.

Brochu, C. (2001). Crocodylian Snouts in Space and Time: Phylogenetic Approaches Toward Adaptive Radiation Integrative and Comparative Biology, 41 (3), 564-585 DOI: 10.1093/icb/41.3.564

- . 2003. Phylogenetic approaches toward crocodylian history. Annual Review of Earth and Planetary Science 31, 357-397.

- . 2007. Morphology, relationships, and biogeographical significance of an extinct horned crocodile (Crocodylia, Crocodylidae) from the Quaternary of Madagascar. Zoological Journal of the Linnean Society 150, 835-863.

Busbey, A. B. 1995. The structural consequences of skull flattening in crocodilians. In Thomason, J.  J. (ed) Functional Morphology in Vertebrate Paleontology. Cambridge University Press (Cambridge), pp. 173-192.

Eaton, M. J. 2010. Dwarf Crocodile Osteolaemus tetraspis. In Manolis, S. C. & Stevenson, C. (eds) Crocodiles. Status Survey and Conservation Action Plan. Third Edition, pp. 127-132. Crocodile Specialist Group, Darwin.

Eaton, M. J., Martin, A., Thorbjarnarson, J. & Amato, G. 2009. Species level diversification of African dwarf crocodiles (genus Osteolaemus): a geographic and phylogenetic perspective. Molecular Phylogenetics and Evolution 50, 496-506.

Frey, E. 1988. Das Tragsystem der Krododile [sic] – eine biomechanische und phylogenetische Analyse. Stuttgarter Beiträge zur Naturkunde Serie A (Biologie), 426, 1-60.

Gatesy, S. M. 1997. An electromyographic analysis of hindlimb function in Alligator during terrestrial locomotion. Journal of Morphology 234, 197-212.

Hutchinson, J. R., Bates, K. T., Molnar, J., Allen, V. & Makovicky, P. J. 2011. A computational analysis of limb and body dimensions in Tyrannosaurus rex with implications for locomotion, ontogeny, and growth. PLoS ONE 6(10): e26037. doi:10.1371/journal.pone.0026037

Martin, J. E. & Benton, M. J. 2008. Crown clades in vertebrate nomenclature: correcting the definition of Crocodylia. Systematic Biology 57, 173-181.

McAliley, L. R., Willis, R. E., Ray, D. A., White, P. S., Brochu, C. A. & Densmore, L. D. 2006. Are crocodiles really monophyletic? – Evidence for subdivisions from sequence and morphological data. Molecular Phylogenetics and Evolution 39, 16-32.

Naish, D. 2001. Fossils explained 34: Crocodilians. Geology Today 17 (2), 71-77.

Norell, M. A., Clark, J. M. & Hutchison, J. H. 1994. The Late Cretaceous alligatoroid Brachychampsa montana (Crocodylia): new material and putative relationships. American Museum. Novitates 3116, 1-26

Persons, W. S. & Currie, P. J. 2011. The tail of Tyrannosaurus: reassessing the size and locomotive importance of the M. caudofemoralis in non-avian theropods. The Anatomical Record 294, 119-131.

Romer, A. S. 1923. Crocodilian pelvic muscles and their avian and reptilian homologues. Bulletin of the American Museum of Natural History 48, 533-552.

Ross, F. D. 2006. African dwarf-croc quandary persists. Crocodile Specialist Group Newsletter 25, 19-21.

- . & Mayer, G. C. 1983. On the dorsal armor of the Crocodilia. In Rhodin, A. G. J. & Miyata, K. (eds) Advances in Herpetology and Evolutionary Biology. Museum of Comparative Zoology (Cambridge, Mass.), pp. 306-331.

Rossmann, T. 2000. Studies on Cenozoic crocodiles: 4. Biomechanical investigation on the skull and the neck of the Palaeogene crocodile Pristichampsus rollinatii (Eusuchia: Pristichampsidae). Neues Jahrbuch fur Geologie und Paläontologie, Abhandlungen 215, 397-432.

Salisbury, S. W. & Frey, E. 2000. A biomechanical transformation model for the evolution of semi-spheroidal articulations between adjoining vertebral bodies in crocodilians. In Grigg, G. C., Seebacher, F. & Franklin, C. E. (eds) Crocodilian Biology and Evolution. Surry Beatty & Sons (Chipping Norton, Aus.), pp. 85-134.

- . & Willis, P. M. A. 1996. A new crocodylian from the Early Eocene of eastern Queensland and a preliminary investigation of the phylogenetic relationships of crocodyloids. Alcheringa 20, 179-226.

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! Follow on Twitter @TetZoo.

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





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  1. 1. Jurassosaurus 1:55 pm 05/24/2012

    Another neat thing about Osteolaemus is their super-swept back post-dentary bones of the mandible. This brings the articulars almost in line with the squamosals (it also gives their skulls a demon smile). This should increase the mechanical advantage of m.depressor mandibulae, resulting in a more powerful jaw opening. It certainly results in an impressive gape for these “little” guys.

    Link to this
  2. 2. Heteromeles 3:01 pm 05/24/2012

    I signed and shared the whitehouse.gov petition. It’s a great cause, and I hope it gets us all somewhere. As someone without an institution paying for my journals, I’m severely limited in what I can access.

    In fairness, I should point out that whitehouse.gov is the usual US government pain in the behind to sign on, so allot twice the time you think it should take, because you have to create an account, with a password, and wait for them to acknowledge it. Also, they will whine if your password doesn’t include numbers and punctuation (not that they’ll tell you this until they sneer at your first password attempt), so you might get through faster if your password is gobbledygook that only a computer can remember. You may also have to logout and log back in to get to the point where you can sign the petition.

    Anyway, the warning is so that you know what you’re stepping into before you go for it. Croc butts may be a bit more simple and appealing, but the signing effort is worth it.

    Link to this
  3. 3. Kelly Clowers 3:34 pm 05/24/2012

    I will sign the .gov petition at home tonight

    I wanted to complain to SciBlogs about the comments, because that is just not right. But their “contact us” link seems to be broken…

    Link to this
  4. 4. naishd 4:11 pm 05/24/2012

    Thanks for comments. It took me a total of two minutes to register and sign on at Whitehouse.gov – I found it really quick and easy, and I assume that this is true for everyone else.

    Darren

    Link to this
  5. 5. Heteromeles 4:25 pm 05/24/2012

    @Darren: it took me about 15 minutes, but a bunch of this was waiting for the reply emails, and a bunch more was figuring out that you have to log out and log back in if they weren’t accepting that you’d just created a password. One of my friends gave up, after running into the same silliness. Perhaps we’re hassled because we’re US residents? I don’t know.

    Regardless, I think it’s a worthwhile effort. I just don’t want people to quit at the first hassle, as my friend did.

    Link to this
  6. 6. naishd 5:02 pm 05/24/2012

    Huh, weird. Ok, sorry to hear about that.

    Darren

    Link to this
  7. 7. Mythusmage 8:58 pm 05/24/2012

    Nice article, now when are you going to write up the domestic gorgonopsian?

    Alan “Maintaining Tradition” Kellogg

    Link to this
  8. 8. CS Shelton 9:52 pm 05/24/2012

    Where do mahajangasuchids fit into that cladogram? I had to cut and paste that word, no way I’m memorizing it.
    :-P

    Link to this
  9. 9. llewelly 10:35 pm 05/24/2012

    The art for notosuchia (the one on the lower left in the first image, and the third one from the top in the second image) looks like a hominid in a croc suit. Coming soon to a cheap movie near you …

    Link to this
  10. 10. llewelly 10:38 pm 05/24/2012

    er, I meant the one identified as sebecosuchian in the caption to the first image. (I’m assuming sebecosuchian is considered a subset of notosuchia. )

    Link to this
  11. 11. Dartian 2:29 am 05/25/2012

    Darren:
    the comments have gone. That’s a major loss.

    Understatement of the day! Unbelievably inept and/or careless by ScienceBlogs.

    Personally, however, I had kind of braced myself for something like this to happen eventually. That was one of the reasons (though not the only one, nor even the most important one) why I originally made the decision to post comments on Tet Zoo under a pseudonym rather than my real name. A way of not getting too emotionally or intellectually attached to potentially ephemeral internet comments, or something like that.

    It still totally sucks if the comments are gone for good, though.

    Frey, E. 1988. Das Tragsystem der Krododile [sic]

    :) I bet Eberhard Frey is still today embarrassed about that one (even it chances are that they typo was not his fault, but the journal’s).

    Does anyone know of other examples of obvious typos in the titles of scientific papers? (I mean genuine typos, not merely alternative or archaic spelling that would have been considered correct at the time of publication.) The more prestigious the journal, the better.

    By the sheerest of coincidence, I happened to come across one just a couple of days ago. Osorio & Vorobyev (2005) published a paper in Proceedings of the Royal Society B which, according to the title, was about “photoreceptor sectral sensitivities” (it should of course be “spectral”).

    Other examples, anyone?

    Reference:
    Osorio, D. & Vorobyev, M. 2005. Photoreceptor sectral [sic] sensitivities in terrestrial animals: adaptations for luminance and colour vision. Proceedings of the Royal Society B 272, 1745-1752.

    Link to this
  12. 12. Dartian 2:38 am 05/25/2012

    even it chances are

    And whaddaya know! I managed to include a typo myself right there. Instant karma, or something. ;)

    Link to this
  13. 13. naishd 4:09 am 05/25/2012

    Gorgonopsians (comment 7): non-mammalian synapsids appearing here soonish, honest!

    Position of mahajangasuchids (comment 8): as usual, different positions have been recovered for the Mahajangasuchus + Kaprosuchus clade. It’s on the Notosuchia branch acccording to some trees, and closer to Crocodylia than to Notosuchia in others.

    “The art for notosuchia (the one on the lower left in the first image, and the third one from the top in the second image) looks like a hominid in a croc suit” (comment 9).

    Oh really? (smiley). Well, your mom looks like a hominid in a croc suit. In seriousness, I tried to give it some appropriately gracile proportions (it’s actually Bretesuchus, a taxon known only from cranial material, I think).

    Darren

    Link to this
  14. 14. naishd 4:25 am 05/25/2012

    The issue with comments on Tet Zoo ver 2: I’ve been concerned for a while that ScienceBlogs might delete some, most or even all of ver 2 for a while. After all, I’m no longer there and it’s effectively up to them what they do with stuff hosted on their servers. In anticipating of this possible event, I asked a friend to do some sort of backup thing. I need to see how that’s going.

    As for typos in titles, there are quite a few out there. A quick search of my tetrapod bibliography reveals…

    Beatty, B. L. 2003. Review: Secondary Adaptations of Tetrapods to Life in Water: Proceedings of the International Meeting Poiteirs [sic]. Journal of Vertebrate Paleontology 23, 474-475.

    Boev, Z. 2002. Distribution of the Little bustard (Tetrax tetrax Linnaeus, 1758) and the Greate [sic] bustard (Otis tarda Linnaeus, 1758) (Aves: Otitidae Gray, 1845) in Bulgaria during the Late Pleistocene and the Holocene. Annual of Sofia University “St. Kliment Ohridski”, Faculty of Biology, Book 1 – Zoology 93-94, 41-47.

    Bonilla, A. J., Braun, E. L. & Kimball, R. T. 2010. Comparative molecular evolution and phylogenetic utility of 3’-UTRs and introns in Galliforms [sic]. Molecular Phylogenetics and Evolution 56, 536-542.

    Candeiro, C. R. A., Abranches, C. T., Abrantes, E. A., Avilla, L. S., Martin, V. C., Moreira, A. L., Torres, S. R. & Bergqvist, L. P. 2004. Dinosaurs [sic] remains from western Sao Paulo state, Brazil (Bauru Basin, Adamantina Formation, Upper Cretaceous). Journal of South American Earth Sciences 18, 1-10.

    Dong, Z.-M. & Tang, Z.-l. 1984. Noteon [sic] a new Mid-Jurassic sauropod (Datousaurus bashanensis gen. et sp. nov.) from Sichuan Basin, China. Vertebrata PalAsiatica 22, 69-74.

    Ellinger, T. U. H. 1950. Camarosaurus [sic] annae – a new American sauropod dinosaur. The American Naturalist 84, 225-228.

    Gresson, R. A. R. 1966. Pilot whales, Globiocephala [sic] melaena (Traill) stranded at Cloghane, Co. Kerry. The Irish Naturalists’ Journal 15, 163-166.

    Ivakhnenko, M. F. & Kurzanov, S. M. 1978. Mesonosaurus [sic], a primitive archosaur. Paleontology Journal 1978 (1), 139-141.

    Kellner, A. W. A. 2001. A new hypothesis os [sic] pterosaur phylogeny. In Barros, L. M., Nuvens, P. C. & Filgueira, J. B. M. (eds) I el II Simpsosios Sobre a Bacia do Araripe e Bacias Interiores do Nordeste, Realizados em Junho de 1990 e Novembro de 1997, Comunicações. Universidade Regional do Cariri – Urca (Crato, Brazil), p. 43.

    Koretsky, I. A. 2001. Morphology and systematics of Miocene Phociane [sic] (Mammalia: Carnivora) from Paratethys and the North Atlantic region. Geologica Hungarica Series Palaeontologica 54, 1-109.

    Mangiacopra, G. 1993. A Camp [sic] trilogy: part one, hunting for Champ. Of Sea and Shore 16 (1), 43-52.

    Mead, A. J. & Wall, W. P. 1998. Paleoecological implications of the craniodental and premaxilla morphologies of two rhinoceroroids [sic] (Perissodactyla) from Badlands National Park, South Dakota. In Technical Report NPS/NRGRD/GRDTR-98/1, pp. 18-22.

    Olson, S. L. 1974. Tantalus milneedw ardsii [sic] Shufeldt – a synonym of the Miocene pheasant Miophasianus altus (Milne-Edwards). The Wilson Bulletin 86, 110-113

    Oshiro, I. & Hasegawa, Y. 1998. On a Mio-Pliocene Trionyx from Lower Shimajira group of Ogami-jima, Miyako Iislands [sic], Okinawa, Japan. Bulletin of Gunma Museum of Natural History 2, 109-112.

    Palmqvist, P. & Vizcaíno, S. F. 2003. Ecological and reproductive constraints of body size in the gigantic Argentavis magnificens (Aves, Theratornithidae [sic]) from the Miocene of Argentina. Ameghiniana 40, 379-385.

    Parker, M. & Farrel, D. 1977. Luth or leather-back turtle, Demochelys [sic] coriacea (L.) at Duncannon, Co. Wexford. The Irish Naturalists’ Journal 19, 51.

    Perrins, C. 1992. Bird Life: An Introduction to the World of Birds. Magna Books (Liecester [sic]), pp. 160.

    Pilleri, G. 1971. Original description of the Gangetic dolphni [sic], Platanista gangetica, attributed to William Roxburgh. Bulletin of the British Museum of Natural History (Zoology) 21, 345-348.

    Riggs, E. S. 1901. The fore leg and pectoral girdle of Morosaurus, with a note on the genus Camarosaurus [sic]. Field Columbian Museum, Publications in Geology 1, 275-281.

    Taylor, M. A. 2000. Functional significance of bone ballastin [sic] in the evolution of buoyancy control strategies by aquatic tetrapods. Historical Biology 14, 15-31.

    Vasse, D. & Hua, S. 1998. Crocodilians [sic] diversity during the Upper Cretaceous and Paleogene. Influence and limits of the Maastrichtian-Paleocene crisis and “Terminal Eocene Events”. Oryctos 1, 65-77.

    Walkden, G. M., Fraser, N. C. & Muir, J. 1987. A new specimen of Stenosauraus [sic] (Mesosuchia, Crocodilia) from the Toarcian of the Yorkshire coast. Proceedings of the Yorkshire Geological Society 46, 279-287.

    Nothing impressive.

    Darren

    Link to this
  15. 15. Heteromeles 12:49 pm 05/25/2012

    Here’s my favorite title screwup, although it’s a really minor journal:

    Kotanen, P. 1994. The effects of fetal pigs on grasslands. Fremontia 22(2) 14-17.

    http://docubase.berkeley.edu/cgi-bin/pl_dochome?query_src=pl_search&collection=Fremontia&id=184

    Link to this
  16. 16. JoseD 11:33 pm 05/25/2012

    @Naishd

    You’ve probably never heard of me, but I’ve been following Tet Zoo on-&-off for a while now (Ask Albertonykus; He’s an online friend of mine). The main reason for this comment is to let you know that, for what it’s worth, you can still see the Tet Zoo V2 comments if you Google the blog posts & then click the Cached button. Hope this helps.

    Link to this
  17. 17. naishd 11:52 am 05/26/2012

    JoseD: thanks for this. I’ve checked it out and it seems to work.

    So, idiot guide for accessing comments on Tet Zoo ver 2…

    – google the title of the specific article you’re interesting in (you have to know, or find, the title – or part of it, at least – in advance).
    – on the google results page, mouse over the article’s title. A double arrow should appear at right.
    – hover on the double arrow and a screen-grab of the article should appear at right, together with the title, url, and ‘cached’ and ‘similar’. Click on ‘cached’.
    – you should then be taken to a cached version, with all comments intact. The formatting is nothing like what it was, but this is better than nothing for now.

    Darren

    Link to this
  18. 18. Mark Robinson 2:54 am 05/27/2012

    I have nothing to add regarding the main article (another good read, thanks) but do have something small for both of the supplementary ones.

    Re Tet Zoo ver 2: that’s terrible news as the comments threads generally add substantial value to Darren’s posts.

    Though I wouldn’t be relying on Google’s caching of the pages to always provide an on-line back-up. A cache is a record of the page at the time it was last crawled. Google’s web-crawlers note how frequently web pages are updated and the crawl frequency of those individual urls is adjusted accordingly. So pages that hadn’t had any new comments or other changes for some time would prob not be crawled again for “a while”.

    However, once the page is crawled again, the cache will presumably be updated to reflect its current devoid-of-comments state. So, enjoy it while it lasts.

    Regarding creating an account in order to sign the Whitehouse petition (and account email verification in general): I have found that any long delay in waiting for the verification email is almost always due to configuration settings on the client-side rather than the issuing server taking its time or other “slow internet” causes.

    Occasionally it may be the configuration or workload of the mailserver which you are using (so, still clien-side) but mostly it is simply how often your email client checks for new mail. Some of the default settings for this are a joke. (MS Outlook’s 30 minutes is clearly a hang-over from the dial-up days of late last century).

    Finally, the SV-POW! link in the last para is wrong, prob a copy-paste error.

    Link to this
  19. 19. naishd 5:20 am 05/27/2012

    Thanks, Mark – link now corrected.

    Darren

    Link to this
  20. 20. Heteromeles 10:51 am 05/27/2012

    @Mark, if by client-side server, you mean the company that handles my email, I’d agree. I was clicking on refresh until the message appeared (about four minutes), not waiting for an auto-refresh. Otherwise…no, I didn’t enjoy the whitehouse login. This included their ingenious “Create an account without generating a password, verify that (email link 1), then create a password (with a number and a punctuation, not that it says that), then verify that you created a password (email link 2), then log in” routine. Then I had to figure out why, when I logged on, I couldn’t sign the petition. It turned out that I had to log out first, before I could log back in to sign the petition. All told, about fifteen minutes. I wasn’t the only person to have the problem, and the fact that it’s on the Whitehouse FAQ suggests that they are aware of the problem and have decided that it’s not worth fixing.

    Personally, I’m glad other people are having better experiences.

    Link to this
  21. 21. David Marjanović 7:58 pm 05/28/2012

    As I’ve said on the preceding thread, at least one other ScienceBlog has had its comments restored. So I suppose there still is hope.

    Are you seriously trying to use Crocodilia and Crocodylia in different ways, instead of considering the former just Owen’s attempt to correct Laurenti’s flawed Greek? Would surprise me if that worked.

    The clade in your figure is Suchia, a subset of Crurotarsi.

    The PhyloCode recommends against names such as Pseudosuchia, precisely because it would contain Suchia while its name explicitly suggests otherwise. Let’s treat Crurotarsi as having undergone an unrestricted emendation.

    I had to cut and paste that word, no way I’m memorizing it.

    Mahajanga.

    Ma-ha-jan-ga.

    The fuck did you have to cut and paste that word. It’s almost as simple as a word with 4 syllables can be!

    Link to this
  22. 22. naishd 4:15 am 05/29/2012

    David (comment 21): I’m not suggesting use of formal Crocodilia for anything, but most people still imagine Crocodylomorpha to be equivalent to ‘crocodilians’ of tradition. As I said above, in vernacular usage it might still be appropriate to use ‘crocodilians’ for Crocodylomorpha. Yes, the cladogram above shows the “Rauisuchia” + Aetosauria + Crocodylomorpha clade, and this is indeed Suchia as defined by Parrish, Sereno and so on. I was aiming, however, to depict the whole of the croc-line clade and wanted the most inclusive name. For now, that’s Pseudosuchia (especially since it’s branch-based).

    Darren

    Link to this
  23. 23. David Marjanović 5:53 am 05/29/2012

    Sorry: you want to use “crocodilians” and “crocodylians” in different ways.

    Link to this
  24. 24. CS Shelton 8:41 am 05/29/2012

    Well, I guess if I got majungasaurus down I can handle this. Plus the vowels are all As… Hm… mahajangasuchids… Ugh. It sounds like a noise someone would make when starting to vomit.
    M-ha
    Jng-A
    BLWARGGG.

    Link to this
  25. 25. Jurassosaurus 9:15 am 05/29/2012

    I don’t remember exactly when it started, but “crocodilian” and “crocodylian” have been used to mean to separate things since at least the early nineties. I think it was Benton and Clarke that emended the name back in 86, or 88. It was done to increase the clarity of the term (since crocodilian was basically a wastebin for any non-ornithodiran archosaur).

    Link to this
  26. 26. Indarctos 9:11 pm 05/29/2012

    I go with David M: either Crurotarsi (blech) or just plain ol’ Sucha or whatever to delineate the LCA of the croc-line of Archosauria.

    Link to this
  27. 27. Mythusmage 9:49 pm 05/29/2012

    In the orginal version of L. Spraqrue deCamp’s “Lest Darkness Falls” where one of the two men sent back in time to 6th century AD Rome is listening to the people talking (he’s a Latin scholar) and his response to what he hears is, “They’re mangling the language!” As you can see, people have been mangling languages for a long time now. :)

    Link to this
  28. 28. CS Shelton 12:12 am 05/30/2012

    Sprechen of LCAs, what do you suppose the dino/croc LCA looked like? Something like a smallish, tall-walking, quadrupedal, carnivorous, land-adapted, warm-blooded, scaly croc-thing, right?

    Link to this
  29. 29. David Marjanović 11:02 am 06/2/2012

    Something like a smallish, tall-walking, quadrupedal, carnivorous, land-adapted, warm-blooded, scaly croc-thing, right?

    Yes, except I’m not sure about “warm-blooded”. Imagine something like Euparkeria, Turfanosuchus, Yonghesuchus and Gracilisuchus.

    Link to this

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