Sunday, December 9, 2012

A Field Guide to Mesozoic Birds and Other Winged Dinosaurs

Those who read my lowly blog will no doubt be familiar with the work of Matt Martyniuk. As an incredibly talented paleoartist, Matt's restorations of prehistoric life are both aesthetically appealing and meticulously researched. In particular, he specializes in (and is probably best known for) depicting Mesozoic birds (=Aviremigia in his personally preferred usage). Additionally, he is a founding member of WikiProject Dinosaurs, a collaborative project that aims to increase the quality of Wikipedia dinosaur articles, and is single-handedly responsible for many of the life restorations and (especially) iconic scale charts present on the online encyclopedia.

One of the greatest contributors to the excellence of Matt's paleoart is the sheer thought and research that has been put into them. Many of the posts on his blog, DinoGoss, discuss aspects of paleoart that are frequently glossed over and yet immensely crucial to the field, such as the processes and biological significance behind feather colors. For this reason I have long thought that it would be magnificent if Matt wrote a self-illustrated book on restoring Mesozoic birds.

As it turns out, he did. About a month ago he teased us all with a picture of the following book cover on Facebook, and later wrote a more extensive article about the subject on DinoGoss.

The book is now out. Having spent two years in the making (so that's why Matt hasn't uploaded much on his DeviantArt for a while), for most part the book does not disappoint. The first few sections of the book detail the evolution and diversity of Mesozoic birds as well as things to take into account when restoring them, some of these incorporating updated versions of DinoGoss posts. Being the very topics I'd hoped Matt would cover were he to write a book, I found these chapters highly enjoyable and they will doubtless serve as a useful guide to other paleoartists looking to illustrate Mesozoic avifauna. Longtime followers of Matt will likely be able to identify nods to his online interactions and activities. Case in point, in order to demonstrate how feathers can obscure skeletal features, Matt uses the deinonychosaurs Troodon and Saurornitholestes to show that even dinosaurs that are supposedly anatomically disparate may have been hard to distinguish in life were we armed only with skeletal characteristics for identification, the same genera Mickey Mortimer used as an example in a comment on DinoGoss.

The main bulk of the book is presented in, as the title implies, a field guide format. With two chapters on oviraptorosaurs, five on deinonychosaurs (and some phylogenetically ambiguous paravians), one on non-ornithothoracine avialans, four on enantiornithines, and five on Mesozoic euornithines, each preceded by a phylogeny indicating the likely positions of taxa discussed, this presents near-comprehensive coverage on the known extent of aviremigian variety in the Mesozoic. Life restorations of almost all known Mesozoic aviremigian species are present, often shown in multiple views, poses, and sometimes ontogenetic stages, each accompanied by a scale chart done in Matt's recognizable style. For a great many aviremigian species, especially avialans, these are likely the first time they have been seriously restored, much less in print. Ornithologically savvy readers will be able to identify choices in coloration inspired by modern birds, though none fall into the trap of being a direct ripoff of a modern species. The succinct but informative text (as is typical for a field guide) lays down the physical characteristics, habitat, and known natural history of each taxon. Much of this will be a great help for buffing up the descriptions in my own list of maniraptors, again particularly with respect to avialans. There are a few cases where I felt that certain interesting facts that could have been added were missing, like Sinornithosaurus being known to have been preyed on (or at least eaten) by the compsognathid Sinocalliopteryx, but such preferences delve into the subjective side of things. Species too fragmentary to be reliably restored are listed in an appendix at the end of the book.

The book is immensely up to date, including even the last aviremigian to be published prior to its launch (Shengjingornis) and incorporating new research on the number of covert layers present in basal aviremigians. A recent paper that heavily influences the content of the book but came out too late to be extensively incorporated was the description of wings in ornithomimosaurs. Though the wing feathers of these specimens are not directly preserved, the authors of the study suggest they were pennaceous, potentially making ornithomimosaurs (and thus all maniraptoriforms) aviremigians. Should this be the case, any subsequent editions or companion volumes to this book would have to include at least ornithomimosaurs, therizinosaurs, and alvarezsaurs in addition to the groups it already has. Commendably, this discovery does get acknowledged in the introductory chapters of the book, and either way this does not cheapen this guide's value. Science marches on is an inevitable acquaintance of the best of us, and the book remains an indispensable reference for the groups it has managed to include.

If there's anything that does remotely detract from this gem, it's the typos. While on the whole they don't hamper the usefulness of the book, typos are abundant enough to be noticeable, especially to paleo-savvy readers. Most of these are spelling errors, but the most glaring example is that Cryptovolans is incorrectly stated to hail from the Upper Cretaceous Dinosaur Park Formation in Alberta, Canada. More extensive proofreading could've considerably increased the quality in this regard.

A bibliography is available at the back of the book, which I approve of (the last reference listed even has quite a bit of tongue-in-cheek humor to it), though I do feel that even more references could have been included. For instance, Velociraptor being known to have scavenged was evidently based on Hone et al. (2010), and yet this paper was not listed as a source. There are also countless specimen description papers that must've been referenced in a project of this type but are not mentioned. Although creating an exhaustive bibliography may not have been the main purpose of this book, it does appear strange to me that only some of the references used were credited. This is arguably especially important for the unpublished tidbits that are brought up. For example, Tianyuraptor is said to have had long neck feathers based on an undescribed mid-sized dromaeosaurid that preserves this feature and may be a specimen of said taxon. Those who are aware of this specimen will know the source of this, but those who know Tianyuraptor only from its published description (based on a specimen that preserves no feathers at all) may well be confused by this information.

There are also a few unexplained omissions to the list of Mesozoic aviremigians. Borogovia, Pamparaptor, Shanag, Otogornis, and Longchengornis are neither included as field guide entries nor mentioned in the appendix (or anywhere else that would explain their truancy). Hesperonychus is also bizarrely absent, despite being namedropped in one of the introductory chapters. (Edit: And Alethoalaornis too. See comments for more on the situation with these MIA taxa; thanks for chiming in, Matt!)

These are but quibbles, outweighed immeasurably by the book's numerous finer points, and if this review appears to imply otherwise it is only because I hold this work to such high standards. This is a book I'd recommend to everyone with an interest in some of the most wonderful of all creatures (i.e.: birds) and easily deserves a place of its own among works of this genre.