This article was published in Scientific American’s former blog network and reflects the views of the author, not necessarily those of Scientific American
Recent months have seen the publication of several new dinosaur-themed books, and in this and several future articles I want to share brief thoughts on them. This article represents another effort to get through my backlog of books-needing-reviews. To work...
Matthew P. Martyniuk’s Beasts of Antiquity: Stem-Birds in the Solnhofen Limestone is a new, fantastically well-illustrated volume devoted entirely to the pterosaurs and dinosaurs of Upper Jurassic German’s Solnhofen Limestone (Martyniuk 2014). The Solnhofen Limestone is a well known limestone deposit that, thanks to exceptionally fine-grained sediment and the tropical, lagoonal habitat it was deposited in, preserves incredibly beautiful, complete fossils, the most famous of which are those of Archaeopteryx, the fabled ‘first bird’. Beasts of Antiquity is similar in size and shape to All Yesterdays (Conway et al. 2012) but contains more text. It combines a general discussion of the Solnhofen Limestone and its fossils with a field-guide style look at the pterosaurs and dinosaurs. We get to see the illustrated species in dorsal ‘flight plan’ view as well as in lateral profile. There are also ‘fact boxes’ showing the species scaled relative to a human (Pioneer Dork of Wikipedia fame).
Introductory sections set the scene by discussing the history of fossil collecting at Solnhofen and the palaeoecology of the region during Late Jurassic times. It seems poorly known outside the world of Mesozoic specialists that Archaeopteryx and other non-marine Solnhofen animals inhabited an archipelago of hot, arid, essentially tree-less islands located at the northern edge of the western Tethys Sea, flanked to the south by reefs (sponge reefs, I think). There’s some evidence for low, scrubby vegetation on these islands, but all those pictures of Archaeopteryx clambering about in the branches or on the trunks of giant trees might be misleading and even completely erroneous.
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I want to note, however, claims that tree fossil were known from the region (apparently including tree trunks) but were destroyed during WWII. I don’t know how reliable these claims are (they’re mentioned here and there by authors who aren’t exactly renowned for lack of bias. A reviewer of an article I wrote once recommended that I mention them after I’d said that Archaeopteryx inhabited a tree-less environment). Martyniuk (2014) is aware of this controversy and notes that the remains of trees – including tree pollen – are absent from the Solnhofen fossil record, even a single alleged ginkgo leaf from the sediments being of doubtful identity.
The bulk of the book is formed of species-by-species coverage of the Solnhofen pterosaurs and theropods. Seeing as most are pterosaurs, this means that the better part of the book is devoted to pterosaurs. Pterodactylus antiquus, Gnathosaurus subulatus, Ctenochasma elegans, Rhamphorhynchus muensteri, Scaphognathus crassirostris, Germanodactylus rhamphastinus (of course, it should really be ramphastinus), Ardeadactylus longicollum, Cycnorhamphus suevicus, Germanodactylus cristatus and Anurognathus ammoni are all discussed and form the focus of colour plates. The as-yet-unnamed ‘Painten pro-pterodactyloid’ is illustrated and discussed as well; Bellubrunnus and ‘Rhamphodactylus’ are mentioned but not illustrated or discussed at length since they aren’t from the Solnhofen Formation (but from older strata). That’s a bit of a shame, as I would have appreciated his take on these specimens (are those weird, forward-curving wing-tips of Bellubrunnus really the case in life, for example?).
The theropod part of the book is far shorter than the pterosaur part: only Compsognathus longipes, Archaeopteryx lithographica and A. siemensii are discussed and illustrated. Juravenator starki and Sciurumimus albersdoerferi are excluded (though Juravenator does feature in one illustration) because, while being from Solnhofen, they’re not from the Solnhofen Formation (Sciurimimus is from the older Rögling Formation, and Juravenator from the also older Painten Formation).
The text is extremely up to date as goes taxonomy, the current state of play as goes synomymisation, and our understanding of life appearance. Some of the things we know about Solnhofen pterosaur soft tissues might surprise those who haven’t been keeping up with the technical literature. Soft tissue head crests have proved widespread in these pterosaurs – it seems that even Scaphognathus had one – and at least some of these animals also had a soft, posteriorly projecting wattle at the back of the head. It’s been argued that the best term for this is ‘lappet’ (Bennett 2013), but Martyniuk suggests that ‘wattle’ or ‘caruncle’ might be more appropriate since ‘lappet’ is already in use for folded skin caruncles (like those of the awesome Lappet-faced vulture Torgos tracheliotus). Another surprise comes from the great size of the tail vanes present in some Rhamphorhynchus specimens.
Filamentous structures termed pycnofibres are preserved on some Solnhofen pterosaurs (and on pterosaur fossils found elsewhere) and show that these animals were covered in a dense pelt when alive. There are good reasons for thinking that pycnofibres might be homologous with the epidermal filaments present in ornithischian and theropod dinosaurs, which might well be homologous with feathers... though, of course, this remains controversial. Martyniuk goes the whole hog and terms all these structures ‘feathers’. I’m not sure I agree with this. I think it’s likely that the filaments of pterosaurs and non-bird dinosaurs are homologous with feathers, but my personal preference is that we should restrict the term ‘feather’ to the branched structures present in maniraptoran theropods.
Anyway, there’s lots to love here. Matt’s life reconstructions of the animals are both accurate and innovative: he shows them with the crests and extensive fuzzy coverings that we now know they had, and he depicts males, females and the members of different growth stages so that we get some idea of what intraspecific variation was like in the species concerned. Juvenile pterosaurs – we generally call them flaplings since Unwin (2005) – from Solnhofen share a list of features with adults but have shorter snouts, proportionally smaller nasoantorbital openings, shorter tooth rows and so on. Such changes have been described for Pterodactylus, Germanodactylus (Bennett 2006) and Ctenochasma (Bennett 2007).
Martyniuk's archaeopterygids are as extensively feathered as evidence indicates they were, with fully feathered faces and legs, and fingers incorporated into the structure of the wing. Those old (and, sadly, sometimes not-so-old) reconstructions that show archaeopterygids with scaly faces and necks – presumably done by artists who wanted these animals to look like bird-reptile ‘hybrids’ or ‘intermediates’ – never were a good idea.
I want to finish this review by saying that the subtitle of this book (Stem-Birds in the Solnhofen Limestone) has caused a bit of discussion. In phylogenetic nomenclature, recall that a lineage with extant members consists of a ‘crown’ (the clade that contains extant species and all descendants of their most recent common ancestor) and a ‘stem’ (the paraphyletic segment of the lineage that encompasses all those fossil taxa that are outside the crown). Incidentally, this is why people are flat-out wrong when they refer to such things as ‘crown-plesiosaurs or ‘crown-ankylosaurs’ – by definition, those groups cannot exist. Anyway, this nomenclatural convention means that all members of the bird lineage outside the crown can be termed stem-birds if you so wish.
Matt is, therefore, absolutely correct in his use of nomenclature: the phrase ‘Stem-Birds in the Solnhofen Limestone’ does accurately describe Solnhofen pterosaurs and those Solnhofen theropods that are outside the modern bird clade. But is this a wise choice of title for a book? It’s not the one I would choose simply because many prospective buyers might be put off; on the other hand, an argument can be made that we shouldn’t assume that authors have to pander to lay-audiences when producing a book such as this.
All in all, I strongly recommend Beasts of Antiquity for anyone interested in dinosaurs (including Archaeopteryx) and/or pterosaurs, and especially for those interested in palaeoart or who like getting an ‘art fix’ from their palaeo-themed books. The book is indexed and includes references. Matt’s previous book – A Field Guide to Mesozoic Birds and Other Winged Dinosaurs – is definitely worth obtaining if you don’t already own it.
Martyniuk, M. P. 2014. Beasts of Antiquity: Stem-Birds in the Solnhofen Limestone. Pan Aves, Vernon, NJ, pp. 112. ISBN 9780988596559. Paperback and ibook, index, glossary and references. Buy it here.
For previous Tet Zoo articles on the topics covered here, see...
Refs - -
Bennett, S. C. 2006. Juvenile specimens of the pterosaur Germanodactylus cristatus, with a review of the genus. Journal of Vertebrate Paleontology 26, 872-878.
- . 2007. A review of the pterosaur Ctenochasma: taxonomy and ontogeny. Neues Jahrbuch fur Geologie und Paläontologie, Abhandlungen 245, 23-31.
- . 2013. New information of body size and cranial display structures of Pterodactylus antiquus, with a revision of the genus. Paläontologische Zeitschrift 87, 269-289.
Unwin, D. M. 2005. The Pterosaurs from Deep Time. New York, Pi Press.