Sunday, January 6, 2013

Review of "A Field Guide to Mesozoic Birds and Other Winged Dinosaurs"

We all know Martyniuk published his field guide of Mesozoic oviraptorosaurs and paravians last month.  How does it hold up?  I was happily surprised to see I was listed (second!) in the acknowledgements and that my Theropod Database is referenced and extensively consulted (though as the website address will change soon, that was unfortunate timing).  I'll try not to let that affect the amount of scathe expected in one of my reviews. ;)

When I was little, I would read field guides instead of story books, and loved the Peterson guides due to their completeness and illustrations.  More than once I started drawing my own, but I don't think I ever got past the grebes (second only to loons in all American field guides, which I now know goes back to Gaddow [1893] and Wetmore and Miller [1926]).  Similarly, I loved Sattler's (1983) "The Illustrated Dinosaur Dictionary", which while not quite in field guide format, did have detailed sequential entries for every dinosaur genus and illustrations of most.  So this book is appealing on a nostalgic level, despite [mostly] not being something I would return to for new technical details.  It's also hot on the heels of Paul's "The Princeton Field Guide to Dinosaurs", which I reviewed and will ellicit comparison.

If any word describes this book, it's 'progressive'.  Ideas are all completely up to date (e.g. the ornithomimid feather paper is used) and the phylogeny is quite good (I don't agree with it all, but it's all well referenced), but it's more than that.  Clades are italicized as if Phylocode were standard already.  Unpublished references are used, and many details which are probably correct but not in the literature yet are used without comment.  Combined with the field guide format, it really does seems like a book written from some enlightened future where we know much more than now.

As a field guide, this is very good.  The restorations are beautiful and extremely believable.  These are some of the only dinosaur illustrations I've seen that seem like real animals.  The coloration and plumage differences between taxa are all just what I'd expect based on recent birds.  If I didn't know better, I'd figure a time machine were involved.  More importantly, the details given to distinguish each species are numerous and accurate.  They almost always reflect what could actually be seen in life.  The habits are almost always stated with the proper amount of uncertainty, and usually explicitly supported by some anatomical detail.  I found these very interesting, as I normally don't think much about the functional reason for differences between taxa.  The use of common names for each species also adds to the illusion these are living creatures and not just objects of scientific study, though as expected of a field guide, scientific names are also provided along with habitat and distribution (both temporal and geographic).

I do have a few issues with it as a field guide.  As in Peterson's guides, arrows point to some distinctive features in the illustrations.  But in Peterson's, these features are italicized in the text and the arrows can overlap the illustration to point out a particular point, so you know exactly what to look for and where it is.  Martyniuk doesn't distinguish arrowed features in the text, and the arrows end a ways from the illustration.  This results in the arrows being almost useless ("so its wing... or maybe chest... is distinctive in some way... hmmm").  Also, sometimes (at least 21 times to be exact) internal anatomy is mentioned as distinctive, but while the details are correct, they aren't things any paleo bird watcher would be able to see ("Is this an Elmisaurus or a Chirostenotes? Time to shoot it and break out the hack saw to check the metatarsal III cross section").  So this takes one out of the feeling this is a field guide instead of an encyclopedia/dictionary.  Another problem is that when more than one individual is shown, it's not immediately obvious what each is representing.  The text usually clears it up, but Peterson's guides contain handy sex symbols, "imm.", "juv.", "adult", etc. so that you immediately know what's shown.  The situation is uncommon in Martyniuk's guide since this kind of variation is known in so few Mesozoic maniraptorans, but it's still an issue.  Finally, it's not always stated when species are based on young individuals (e.g. Microvenator, Eoconfuciusornis), which at least affects size and often other characters.

Scientifically, the book is highly accurate and is probably the best general text on bird origins that exists.  Paul's DoA is more detailed, but also older, more heterodox and a bit daunting to the casual reader.  One way in which Martyniuk's book is heterodox is its use of certain older yet not currently used clade names.  Some are correct according to ICZN rules (Deinodontoidea, Ornithodesmidae, possibly Itemirinae), and these I fully support either using or petitioning the ICZN to officially suppress them.  I should note though, that the ICZN also says if a family contains subfamilies, one has to be eponymous.  Martyniuk doesn't use an Ornithodesminae (and indeed it would be difficult given the uncertain position of Ornithodesmus within Eudromaeosauria), but why stick to one inconvenient rule if you don't follow another?  Other names (Ornithosuchia for avemetatarsalians, Segnosauria, Caenagnathiformes, Saurornithes, Odontoclae) aren't covered by the ICZN, and while I like Martyniuk's sentiment in wanting older names to retain priority, I think these are a lost cause.  If we're going back to 1800's names, we should be calling Theropoda Goniopoda.  I'm not for an Ornithosuchia which does not contain Ornithosuchus, so would reject that name.  I do regret Segnosauria's loss to Therizinosauria.  But Clarke (2004) brought Ichthyornithes back for Ichthyornithiformes, so maybe there's some hope?  Other names used are not standard, like Metatheropoda, Aviremigia and Chuniaoae.  Ditto for his new combination Saurornitholestes explanatus, which is based on and credited to me.  Yet as I state on the Database, while I do think Laelaps explanatus is probably synonymous with Saurornitholestes langstoni, I don't formally synonymize them "because from the limited description, explanatus is indistinguishable from not only Saurornitholestes, but Bambiraptor and Velociraptor as well. It is only referred to Saurornitholestes due to provenance."  I like being credited for the idea, it just hasn't been shown to be correct yet.  Overall, these heterodox names are just an odd thing to include in a field guide.  They add to the impression the book is from a different time where new standards are followed, but will not be good for unfamiliar readers who don't realize this area of the book represents Martyniuk's hopes instead of current thoughts (whereas while the Database uses e.g. Chiniaoae, I also explain its obscure origin).  The fact Martyniuk erects a few new taxa (Ornithes, Ornithodesmiformes) and provides new definitions for many is also odd for a field guide, which are generally popular works where no new science is presented.  The taxa and definitions are a mixed bag, with some being quite good but others quite bad, and my earlier post goes into those details.  Above I mentioned that many unpublished ideas are used without comment, and quite a few of these are mine (Dromiceiomimus brevitertius being the right name for Ornithomimus edmontonicus, Zhongornis as a juvenile confuciusornithid, Omnivoropterygiformes having priority over Sapeornithiformes, Ichthyornis anceps being the correct name instead of I. dispar, possibly oviraptorosaurian Kuszholia, microraptorian Richardoestesia, dromaeosaurine Zapsalis, lithornithid Limenavis, etc.).  On the one hand it's nice to have these out there and know people are listening to my ideas, and at least they aren't presented with arguments in technical papers.  Still I would have liked credit for the more certain, creative ones, though I was acknowledged extensively in the book (my hesperornithine phylogeny which predated O'Connor and Zhou's, my idea on Dapingfangornis' supposed horn, my belief Yungavolucris may be synonymous with Elbretornis based on size).  Jaime will be happy with some common names used for oviraptorids, like mitre-crested egg seizer and big-beaked shell thief.

While most of the information is accurate, there are some details I think are incorrect or unknown, mistakes, etc. in addition to the uncommon misspellings and such.  Yet these issues are rare considering the vast amount of information in the book.
Martyniuk states "the snout of T. formosus would be more pointed at the tip as seen from above [than Saurornitholestes]", which I think was just a mistake, since the Troodon entry states it has a broad snout.

Not an error per se, but I notice Yixianosaurus is still in the basal oviraptorosaur cladogram but not mentioned in the text.  No doubt it was accidentally left there after Martyniuk removed its entry, based on his blog post.
Incisivosaurus gauthieri is stated to be a probable synonym of Protarchaeopteryx robusta, but I don't think this has ever been suggested.
Skull details are given for Caudipteryx dongi, but it only preserves a frontal and pterygoid.
Microvenator is stated to be found in Oklahoma and Wyoming in addition to Montana (where the holotype was found), but only the holotype is known. It's also said to have a short tarsus, but only metatarsal I is preserved.
Chirostenotes elegans is presented as being a sexual variation of C. pergracilis.  I'm not sure why recent authors are trying so hard to dissociate elegans from Elmisaurus, but they really do share characters.  Note for example elegans doesn't have the diamond-shaped metatarsal III proximal section of C. pergracilis, which is even listed as a characteristic of the latter species by Martyniuk.  Instead, the section is triangular as in E. rarus.
Paul's (2010) ideas on oviraptorid synonymy are given credence (though not followed), but are highly unlikely, even moreso given the recent osteology of Khaan (Balanoff and Norell, 2012) which details numerous differences from the Citipati holotype.

Cryptovolans' habitat and distribution are obviously supposed to be those of Hesperonychus, which was seemingly cut from the main section and accidentally not added to the end list of poorly known taxa.
Dromaeosaurus is described as having "Legs relatively long compared to contemporary S. explanatus. Tail more flexible than most other eudromaeosaurians.", but these areas are unknown.  Indeed, Currie (2005) states some RTMP postcrania might be referrable to the genus because it is more robust than Saurornitholestes.
"Sickle claw very small" is listed as a feature of Adasaurus, but it turns out this is wrong (Kubota pers. comm. to Senter, 2010).
Timimus is listed as an unenlagiine, but was more recently determined to be a tyrannosauroid (Benson et al., 2012).
Buitreraptor was listed as having "wing claws short & digits nearly equal in length. Hand unusually short relative to very long humerus & radius/ulna." Yet this is based on the mount, which inaccurately restored the known fragments, which don't indicate any such morphology (Gianechini pers. comm.).
The tiny troodontid skulls from the Citipati nest are referred to Byronosaurus, but I believe the TWG team currently believes they belong to a more basal taxon like the Zos Canyon ?jinfengopterygiine (I'm sure I read this, but can't recall the source; they've gone back and forth so much on this).
"Legs long & slender." was listed as a trait of Zanabazar, but the preserved distal tibiotarsus and proximal tarsometatarsus leave this unknown.
Regarding Philovenator, "Additional specimens from the same time & general area, known as the “Zos Canyon Troodontid”, are probably the same species (Mortimer 2010)." It is nice to be credited, but I actually only "tentatively referred" them to the same species.  Since 2010, Philovenator has been redescribed and we have info on IGM 100/1280 (Zos Canyon specimen) and 100/1323 (both in Turner et al., 2012).  So the idea could use reevaluation.
Euronychodon is in quotes, as is the genus of Paronychodon caperatus.  I'm note sure of the rationale here.

Martyniuk states the "Diet is unknown in [Confuciusornis sanctus]" but consumed fish are preserved in one specimen (Dalsatt et al., 2006).  It could be argued this is a different species as it is from a younger formation and shares a mandibular similarity with C. dui (as I state on my blog), but this is not elaborated in the book.
An "upturned bill tip" is stated as distinctive for C. dui, but is a keratinous bill actually known in C. sanctus?  Even C. dui's premaxilla lacks an upcurved tip, after all.
Shenquiornis "Lacked procoracoid bones".  Oops!  Clearly just a typo.
Piksi, Palaeocursornis and Eurolimnornis are apparently pterosaurs (Agnolin and Varrichio, 2012), but this is forgivable as it was not published until after the book.

So overall this is an interesting book.  As a field guide, it is quite good, far better than Paul's, but still falling short of Peterson's.  It's so up to date it could be from the future, but the illustrations will make you think the author had access to the past.  As a popular reference to bird origins, it is perhaps unmatched in quality, from feathers, to beaks to wings.  It's even pretty good as an encyclopedia of maniraptorans for non-experts, since those rarely use internal details anyway.  More questionable are its attempts to add to the repository of science.  Some of the suggestions are good, others I dislike, but a field guide feels like the wrong place to publish them regardless.  The price of the physical book ($36.99) is quite steep considering Peterson's field guides are $20-26, larger, and far more useful since Martyniuk's species will never actually be seen in the field.  Similarly, though Paul's field guide is worse content-wise, it does contain skeletals, the whole range of Mesozoic non-pygostylian dinosaurs, and is hardcover at $35.  But as a fun and educational introduction to the species of Mesozoic oviraptorosaurs and paravians, I can easily recommend the pdf version at its low price of $9.99.  Thanks to Matt for trying this fascinating format!

Martyniuk, 2012. A Field Guide to Mesozoic Birds and Other Winged Dinosaurs. Vernon, New Jersey. Pan Aves. 189 pp.

Thursday, January 3, 2013

Martyniuk's (2012) new definitions and clades

Martyniuk's "A Field Guide to Mesozoic Birds and Other Winged Dinosaurs" is out, and while most of it is in the form of a popular field guide, it's also filled with a ton of new phylogenetic definitions and some new taxa.  A review of the entire book is in the pipeline, but let's look at this one section of it today.

Aviremigia is officially proposed (note Gauthier and de Quieroz only conditionally proposed it), though contra Martyniuk, the latter would near certainly have used Vultur not Passer, as in all of their bird-based clades.  Since we still don't know how far towards the base of Maniraptoriformes remiges and retrices extend due to possible taphonomic effects, proposing this apomorphy-based clade still seems premature.

We get a definition for Chuniaoae as the oviraptorosaur+paravian group (in most topologies), so we finally have a name for that.  I can't help but think my discussion of this name on the Database is responsible, which I regret a bit as it is such a terrible name and wasn't intended to be so inclusive (it was named as an avialan clade including Caudipteryx+birds).

Caenagnathiformes is defined, and while it is older than Oviraptorosauria, there are no rules saying it must have precedence, and Oviraptorosauria has had basically universal acceptance.  I can't see this being adopted, so I have to wonder why it was proposed.

Caenagnathinae is defined as (Caenagnathus collinsi < Oviraptor philoceratops, Avimimus portentosus), but is rather useless in a topology like mine where Avimimus is a caenagnathid. Ditto for Avimimidae being (Avimimus portentosus < Oviraptor philoceratops, Elmisaurus rarus, Caenagnathus collinsi). Elmisaurinae is used in the next section as sister to Caenagnathinae, but is never defined.  Note that position would make Elmisaurus a caenagnathine in Martyniuk's phylogeny.

Ornithes is proposed for Aves sensu Chiappe- (Archaeopteryx lithographica + Passer domesticus), which is nice to have.

We get a definition for Nicholson's 1878 name Saurornithes (Archaeopteryx lithographica < Passer domesticus), but I pretty strongly disagree with this. It's a synonym of the earlier named Archaeopterygidae (1871; using Xu et al.'s 2011 definition) if Archaeopteryx is avialan or basal to Eumaniraptora; or if Archaeopteryx is deinonychosaurian, it's a synonym of that clade. Though named far before Deinonychosauria, it's not nearly as widely used or well known, and if priority is what matters, why not use the even earlier Sauriurae (1866), which is also better known and used due to BANDITs?

Ornithodesmiformes (Ornithodesmus cluniculus, Dromaeosaurus albertensis, Troodon formosus < Archaeopteryx lithographica) is another name I'm unhappy with.  While I agree Ornithodesmus is probably a dromaeosaurid and Ornithodesmidae has priority over Dromaeosauridae, the need for linked subclades doesn't exist in Phylocode and the ICZN doesn't cover taxa higher than family level.  It's potentially useful when we have basal deinonychosaurs, and Ornithodesmus probably is a member, but there are more secure names that could have been chosen.

I DO like Troodontinae (Troodon formosus + Saurornithoides mongoliensis) though, which has been needed for a while.  Problematically, Saurornithoidinae is listed as a taxon of equal rank in the next section, though it would be a synonym and has never been proposed before.

Ornithodesmidae is used in place of Dromaeosauridae as it was named earlier and defined as (Ornithodesmus cluniculus < Archaeopteryx lithographica, Passer domesticus, Paronychodon lacustris, Pterodactylus antiquus). I'd guess Paronychodon stands in for Troodon as the latter was not named in 1913 when Ornithodesmidae was proposed. The ICZN does give Ornithodesmidae priority, but as it is never used (and not everyone accepts Ornithodesmus is a dromaeosaurid, though their published reasons have been invalid) I would rather the ICZN be petitioned to sink it.

Microraptorinae is defined as a less inclusive microraptorian clade- (Microraptor zhaoianus < Sinornithosaurus millenii, Dromaeosaurus albertensis).  It's useful if Cryptovolans is separate, but otherwise not so much until microraptorian phylogeny is better understood. Also note Turner et al. (2012) already defined this clade as a junior synonym of Microraptoria.

Itemiridae (1976) is defined as (Itemirus medullaris < Dromaeosaurus albertensis, Stenonychosaurus inequalis, Tyrannosaurus rex), which is seemingly to replace Velociraptorinae from 1983. Indeed, it is only referred to in the text as 'itemerine', and Itemirinae is proposed in the next section (which makes that a new name). I'm at a loss why Stenonychosaurus was used this time, as Troodon was named long beforehand and the fact the Stenonychosaurus holotype preserves a braincase wouldn't seem to matter for any part of Phylocode. I think using Itemiridae/inae is a bad choice, as only one analysis has placed Itemirus in Velociraptorinae, and this was only based on one character (basioccipital tubera with distinct, ovoid depressions on the caudal surface).  There are other characters that contradict this, and Miyashita (2011) even found it as a tyrannosauroid in his analysis.

Kudos to Martyniuk for recognizing Omnivoropterygidae/-iformes has priority over Sapeornithidae/-iformes.  Yet his solution puts us in an awkward situation, as he defines Omnivoropteryiformes, but ignores the family (though only the family is used in his taxonomic table).  And yet the family (as Sapeornithidae) is used more often than the order by authors, the ICZN doesn't recognize priority of order-level taxa (so really only the family's priority is mandated), and this is the first definition ever applied to any of these groups AFAIK. So if we want to follow the defined clade name, we have to use a synonym which is barely used AND non-mandated, and not of the same level as the term most authors use. Ack.

I like Martyniuk defining Confuciusornithiformes as (Confuciusornis sanctus < Enantiornis leali, Passer domesticus), since Confuciusornithidae has been defined as (Confuciusornis sanctus + Changchengornis hengdaoziensis) by Chiappe et al. (1999). Other authors (e.g. Zhang et al., 2008) have largely ignored the definition.

Martyniuk defines a LOT of enantiornithine clades, though I don't think our understanding of enantiornithine phylogeny justifies this yet.  For instance, using O'Connor and Zhou's (in press) topology, Iberomesornithiformes, Eoenantiornithiformes and Eoenantiornithidae are all monotypic, Longipterygiformes includes Longipteryx and the probably synonymous Boluochia, and Cathayornithiformes includes Neuquenornis, Eoenantiornis, Conornis, Eocathayornis, Liaoningornis and Eoalulavis in addition to Cathayornis.  I do like that he uses Cau and Anduini's definition of Avisauridae for Avisauroidea, since Avisauridae had been previously defined differently.

Patagopterygiformes is defined, which isn't too useful as no taxa have been found in published analyses to clade with Patagopteryx.  Sure Alamitornis, Kuszholia and Gargantuavis have been proposed, but surely it's better to need a clade before you define it.

Defining Chaoyangiformes is about as useful as those enantiornithine clades, since Chaoyangia's position among 'euornithines' hasn't been established.

Defining Songlingornithidae as (Songlingornis linghensis < Chaoyangia beishanensis, Passer domesticus) works as long as Chaoyangia isn't one, which it seems not to be.  However, defining Yanornithiformes as (Yanornis martini < Passer domesticus) seems like it should be a low priority until there's good evidence Yanornis isn't a songlingornithid.

Similarly, defining Ambiortiformes is nice (Ambiortus dementjevi < Passer domesticus), but then defining Apsaraviformes as a junior synonym in his own topology (Apsaravis ukhaana < Passer domesticus) is just odd.

Martyniuk defines a misspelled Odontolcae (as Odontoclae) as (teeth set in grooves as in Hesperornis regalis). Well, enantiornithines, Yanornis and outgroup avialans have teeth set in sockets (as may Gansus), but Hesperornis and Ichthyornis have them set in grooves.  Aves lack teeth so are inapplicable, which leaves us uncertain where to apply the name, even if we knew the relationships between Hesperornithes, Ichthyornis and Aves, which we don't.  So why ressurrect a name originally idealized as what we call Hesperornithes (Ichthyornis was in Odontormae) and give it a definition which can't be applied to a specific node given our current information?

He defines Odontornithes as (Ichthyornis anceps, Hesperornis regalis < Passer domesticus), but doesn't actually support the clade.  Hmm.  As a nitpick, if Martyniuk's goal was to choose taxa known when the clade was named, I. anceps was still placed in Graculavus in 1873 when Odontodornithes was named, and was not recognized as an odontornithine at the time, so I would have chosen I. dispar.

Hesperornithiformes is defined as (Hesperornis regalis + Enaliornis barretti), which is basically identical in composition to the stem-based Hesperornithes in most(every?) published phylogeny.  Even worse, we don't know how Potamornis and Pasquaornis relate to Enaliornis, nor if the three species of Enaliornis form a clade exclusive of Hesperornis.  So Hesperornithiformes is quite unecessary at the moment.  The same could be said of Enaliornithidae (Enaliornis barretti < Hesperornis regalis).

Based on my phylogeny for hesperornithines, Brodavis (if it includes varneri) falls within Hesperornithidae, so Martyniuk's definition for Brodavidae (Brodavis americanus < Hesperornis regalis) is not only redundant with Brodavis but inside another family.

I like Hesperornithoidea for the (Baptornis advenus + Hesperornis regalis) clade, but I should note Schufeldt (1903) originally named it for more inclusive clade also including Enaliornis.

A definition for Baptornithidae is nice I suppose, but there are no definite members besides Baptornis advenus, so it's redundant currently.

A definition for Gansuiformes is also redundant at the moment.

We already have the older clade Ichthyornithes defined as (Ichthyornis dispar < Struthio camelus, Tinamus major, Vultur gryphus), why define the newer Ichthyornithiformes as (Ichthyornis anceps < Hesperornis regalis, Gansus yumenensis, Passer domesticus)?  I agree including Hesperornis as an external specifier is good, but why not just ammend the definition of Ichthyornithes?  Also, the type species Ichthyornis dispar should be used in a definition based on Ichthyornis, even if I. anceps is a senior synonym.

I have no issue with his new definition for Anseriformes.  Anatoidea should be based on Anas platyrhynchos though, not Anser anser.

The suggested definition for Gaviiformes (crown Gavia immer < Podiceps cristatus, Passer domesticus) would include all of Natatores, Gruiformes, Cuculidae, etc. under molecular phylogenies.

The definition for Charadriiformes (crown Charadrius hiaticula < Passer domesticus) might work, but might also include Natatores, Gruiformes, etc. as well.

So overall, we have some useful definitions (Chuniaoae, Ornithes, Troodontinae, Confuciusornithiformes, Songlingornithidae, Ambiortiformes, Hesperornithoidea), but a large number are currently redundant and some don't even define clades he thinks are valid or are synonyms of other clades he defines.  Others don't have a clear use, as phylogenies of relevent taxa are still in flux.  The emphasis on oldest names is admirable in a way (and I fully support action to either use or officially suppress them for family level taxa), but when not mandated by the ICZN it just causes confusion (following Martyniuk's logic, we would use Goniopoda for Theropoda, Opisthocoelia for Saurischia, etc.).  Martyniuk does do a good job defining most clades though, using eponymous genera and type species for most.

Stay tuned for my feelings on the rest of the book.

Reference- Martyniuk, 2012. A Field Guide to Mesozoic Birds and Other Winged Dinosaurs. Vernon, New Jersey. Pan Aves. 189 pp.