Monday, March 16, 2020

What is Oculudentavis if it's not a theropod?

In my last post, I argued the recently described Oculudentavis (Xing et al., 2020) is not a theropod.  So what is it?  To answer that question, I entered it into Simoes et al.'s (2018) sauropsid analysis which emphasizes basal lepidosauromorphs and comes out with basal gekkos and nested iguanians even using just morphological characters.  To test Jingmai's avialan hypothesis, I also added Archaeopteryx to the matrix.  The result is 384 MPTs of 2337 steps each.

Strict consensus of 384 MPTs of Simoes et al.'s (2018) analysis after adding Oculudentavis and Archaeopteryx.  Compare to Extended Data Figure 3 of Simoes et al..
As you can see, Oculudentavis resolves as a stem-squamate in a trichotomy with Huehuecuetzpalli and squamates, while Archaeopteryx is an archosauromorph sister to Erythrosuchus.  And this matrix didn't score for scleral ossicle shape, posttemporal fenestra size or maxillary tooth row length.  After scoring Oculudentavis, its teeth are clearly not acrodont, it seems to have a ventral parietal fossa and  lacks an ossified laterosphenoid.  The authors could have made it easier to evaluate by separating the cranial elements in the 3D pdf file.  As it is, a lot of palatal and braincase info is uncertain.  But Huehuecuetzpalli is Albian compared to Oculudentavis' Cenomanian, and has a skull length of 32 mm (19 mm in the juvenile) versus 14 mm in Oculudentavis.


Huehuecuetzpalli skull (top; after Reynoso, 1998), Oculudentavis skull and separate mandible (middle; after Xing et al., 2020), and Archaeopteryx skull (after Rauhut, 2014).

References- Reynoso, 1998. Huehuecuetzpalli mixtecus gen. et sp. nov: A basal squamate (Reptilia) from the Early Cretaceous of Tepexi de Rodriguez, central Mexico.  Philosophical Transactions of the Royal Society B: Biological Sciences. 353, 477-500.
Rauhut, 2014. New observations on the skull of Archaeopteryx. Paläontologische Zeitschrift. 88(2), 211-221.

Simōes, Caldwell, Talanda, Bernardi, Palci, Vernygora, Bernardini, Mancini and Nydam, 2018. The origin of squamates revealed by a Middle Triassic lizard from the Italian Alps. Nature. 557(7707), 706-709.



Xing, O'Connor, Schmitz, Chiappe, McKellar, Yi and Li, 2020. Hummingbird-sized dinosaur from the Cretaceous period of Myanmar. Nature. 579, 245-249.

Thursday, March 12, 2020

Oculudentavis is not a theropod

Hi all.  This week we got the announcement of a tiny theropod skull in Myanmar amber, which was bound to happen eventually as amazing finds from that deposit keep being published.  Alas, whatever Oculudentavis is, it's not a theropod.

Oculudentavis skull (after Xing et al., 2020).

Just look at it.  No antorbital fenestra, incomplete ventral bar to the laterotemporal fenestra, huge posttemporal fenestrae, teeth that extend posteriorly far under the orbit...

All of which might be coincidental, but then look at the mandible.

Oculudentavis mandible (after Xing et al., 2020).

That spike-like coronoid process is classic lepidosaur, plus the dentary is way too long compared to the post-dentary elements, then the description says "The tooth geometry appears to be acrodont to pleurodont; no grooves or sockets are discernable."  And of course "the scleral ring is very large and is formed by elongated spoon-shaped ossicles; a morphology similar to this is otherwise known only in lizards (for example, Lacerta viridis)."

Add to this the size of this partially fused specimen being smaller than any extant bird (14 mm), and no feather remains, and why is this a theropod again?  The endocast is big, but why not a clade of brainier lizards or late surviving megalancosaurs by the Cenomanian?

The authors add it to Jingmai's bird analysis where it ends in a huge polytomy closer to Aves than Archaeopteryx, but outside fake Ornithuromorpha.  That's often what happens when a taxon is wrongly placed in a clade.  Note the figured placement between Archaeopteryx and Jeholornis is only found using implied weights.  At least add it to e.g. Nesbitt's or Ezcurra's archosauromorph analyses, or Cau's theropod analyses before assuming it's a bird.

Thanks to Ruben Molina Perez for suggesting this issue in the first place.

Reference- Xing, O'Connor, Schmitz, Chiappe, McKellar, Yi and Li, 2020. Hummingbird-sized dinosaur from the Cretaceous period of Myanmar. Nature. 579, 245-249.

Monday, January 20, 2020

Details on Teinurosaurus and random musings

Hi all.  When updating The Theropod Database I noticed my entry for Teinurosaurus is pathetically bad- wrong authors, wrong age, wrong size, and generally missing the complicated history of this innocuous vertebra.  How embarrassing!  So here's the revised version that will be uploaded-

Teinurosaurus Nopcsa, 1928
= Saurornithoides Nopcsa, 1928 (preoccupied Osborn, 1924)
= Caudocoelus Huene, 1932
T. sauvagei (Huene, 1932) Olshevsky, 1978
= Caudocoelus sauvagei Huene, 1932
Tithonian, Late Jurassic
Mont-Lambert Formation, Hauts-de-France, France

Holotype- (BHN2R 240; = Boulogne Museum 500) incomplete distal caudal vertebra (75 mm)
Diagnosis- Provisionally indeterminate relative to Kaijiangosaurus, Tanycolagreus and Ornitholestes.
Other diagnoses- (after Huene, 1932; compared to Elaphrosaurus) centrum wider; narrower ventral surface; ventral median groove wider; transversely narrower prezygapophyses.
While Huene attmpted to distinguish Teinurosaurus from Elaphrosaurus, only the wider median ventral groove is apparent in existing photos of the former.  This is compared to the one distal caudal of the latter figured in ventral view, but as Kobayashi reports grooves become distally narrower in Harpymimus while Ostrom reports they become distally wider in Deinonychus, groove width is not considered taxonomically distinctive at our current level of understanding.  Indeed, this lack of data is most relevent to both diagnosing and identifying Teinurosaurus.  Very few taxa have detailed descriptions of distal caudal vertebrae or more than lateral views figured, let alone indications of variation within the distal caudal series.  So the facts that Fukuiraptor and Deinonychus share ventrally concave central articulations with Teinurosaurus in their single anteriorly/posteriorly figured distal caudal vertebra, or that Afromimus, "Grusimimus" and Falcarius also have have wide ventral grooves in their few ventrally figured distal caudals, are not considered taxonomically important. 
Comments- Sauvage (1897-1898; in a section written in January 1898) first mentioned a distal caudal vertebra he referred to the ornithischian Iguanodon prestwichii (now recognized as the basal styracosternan Cumnoria prestwichii) - "We are disposed to regard as belonging to the same species the caudal vertebra of a remote region, the part which we figure under n ° 7, 8" [translated].  Note Galton (1982) was incorrect in claiming Sauvage reported on this specimen in his 1897 paper (written December 6), which includes a section on prestwichii nearly identical to the 1897-1898 one but which lacks the paragraph describing this vertebra.  This could provide a specific date of December 1897 to January 1898 for the discovery and/or recognition of the specimen.  Huene (1932) correctly noted Sauvage mislabeled plate VII figure 8 as dorsal view, when it is in ventral view as understood by the text.  Compared to Cumnoria, the caudal is more elongate (length 3.93 times posterior height compared to 2.54 times at most), has a ventral median groove instead of a keel, and the prezygapophyseal base in 71% of the anterior central height compared to ~30-40%, all typical of avepods.  Nopcsa (1928) recognized its theropod nature and in his list of reptile genera meant to use a footnote to propose Teinurosaurus as a "new name for the piece described and figured by Sauvage (Direct. Traveaux Geol. Portugal Lisbonne 1897-1898, plate VII, Fig. 7-10) as late caudal of Iguanodon Prestwichi."  Teinurosaurus is listed as an aublysodontine megalosaurid (not as an ornithomimine, contra Galton), roughly equivalent to modern Eutyrannosauria.  However due to a typographical error, the footnote's superscript 1 was placed after Saurornithoides instead of Teinurosaurus.  Sauvage (1929) corrected this in an addendum- "footnote 1 does not refer to Saurornithoides (line 19 from below) but to Teinurosaurus (last line of text)."  Unfortunately, Huene missed the addendum, and thus wrote "Nopcsa recognized in 1927 (43, p. 183) that this was a coelurosaur and intended to give it a name, but used one already used by Osborn, namely "Saurornithoides" (91, 1924, p. 3- 7). For this reason, a new name had to be given here" [translated].  Huene's proposed new name was Caudocoelus sauvagei, placed in Coeluridae and "somewhat reminiscent of Elaphrosaurus."  Huene is also perhaps the first of several authors to place the specimen in the Kimmeridgian, when it is actually from the Tithonian (Buffetaut and Martin, 1993; as Portlandian).  Galton wrote "Lapparent and Lavocat (1955: 801) gave a line drawing of the vertebra after Sauavage (1898) and included it in the section on Elaphrosaurus" and that the specimen "was referred to Elaphrosaurus by Lapparent and Lavocat (1955)."  This was perhaps done because Huene explicitly compared the two, ironically making it the only taxon distinguished from Teinurosaurus at the time.  Most of Huene's characters cannot be checked in the few published photos of Teinurosaurus, but the ventral median sulcus is indeed much wider than Elaphrosaurus.  Ostrom (1969) was the first author to detail Nopcsa's (1929) addendum, stating "Nopcsa's name Teinurosaurus has clear piority over Huene's Caudocoelus, but since Nopcsa failed to provbide a specific name, Teinurosaurus is not valid."  Olshevsky (1978) solved this by writing "Teinurosaurus has clear priority over Caudocoelus, as noted in Ostrom 1969, and it is certainly a valid generic name. The species Caudocoelus sauvagei is proposed here as the type species of the genus Teinurosaurus, resulting in the new combination Teinurosaurus sauvagei (von Huene 1932) as the proper name of the type specimen."  He also claimed "the specimen itself, unfortunately, was destroyed during World War II and thus must remain a nomen dubium."  This was repeated by Galton, but as Buffetaut et al. (1991) wrote- "Contrary to a widespread opinion (expressed, for instance, by Lapparent, 1967), the vertebra in question has survived two world wars and years of neglect, like a large part of the other fossil reptile remains in the collections of the Boulogne Natural History Museum (see Vadet and Rose, 1986)."  Olshevsky noted Steel misunderstood Nopsca in a different way, believing Teinurosaurus instead of Aublysodon was a "name, proposed by Cope in 1869 ... used instead of Deinodon", as stated under superscript 2.  Galton did have the first modern opinion on Teinurosaurus' affinities, stating "In addition to Elaphrosaurus, elongate prezygapophyses occur in the allosaurid Allosaurus and the dromaeosaurid Deinonychus, so this caudal vertebra can only be identified as theropod, family incertae sedis."  Buffetaut and Martin (1993) agreed, saying "no really distinctive characters that would allow a familial assignment can be observed."  Ford (2005 online) gave the type repository as "Dortigen Museum", but this is a misunderstanding based on Huene's "Boulogne-sur-mer (Nr. 500 im dortigen Museum)", which translated is "Boulogne-sur-mer (No. 500 in the museum there)", referring to the Boulogne Museum where it has always been held.  It was originally number 500, but was recatalogued at some point.
Sauvage lists the vertebra's length as 75 mm and his plate at natural size would have it be 79 mm, Huene lists it as 11 cm (110 mm) and his figure at 1:2 size would have it be 152 mm.  Galton's drawing with supposed 5 cm  scale would have it be 235 mm, while Buffetaut and Martin's plate with scale would leave it at 74 mm.  As Huene's and Galton's figures are taken from Sauvage's original plate and the newest and unique photo matches Sauvage's reported length almost exactly, 75 mm is taken as the correct length.
Relationships- While prior authors haven't specified Teinurosaurus' relationships past Theropoda (besides Lapparent and Lavocat's apparent synonymy with Elaphrosaurus), there are several ways to narrow down its identity.  Only neotheropods are known from the Late Jurassic onward, so coelophysoid-grade taxa are excluded.  Some theropod clades were too small to have a 75 mm caudal, including most non-tyrannosauroid coelurosaurs besides ornithomimosaurs, therizinosaurs and eudromaeosaurs.  The former two are unknown from the Jurassic, and additionally paravians like eudromaeosaurs lack any neural spine by the time the centrum gets as elongate as Teinurosaurus (e.g. by caudal 12 in Deinonychus at elongation index of 2.4).  Teinurosaurus has an elongation index (centrum length/height) of 3.9, which also excludes Ceratosauridae, Beipiaosaurus + therizinosauroids and oviraptorosaurs.  Prezygapophyses basal depth is significantly less in ceratosaurids, megalosaurids, carnosaurs except Neovenator, compsognathids, Fukuivenator and Falcarius.  Remaining taxa are elaphrosaur-grade ceratosaurs, piatnitzkysaurids, Neovenator and basal tyrannosauroids. 
References- Sauvage, 1897. Notes sur les Reptiles Fossiles (1).  Bulletin de la Société géologique de France. 3(25), 864-875.
Sauvage, 1897-1898. Vertebres Fossiles du Portugual, Contributions a l'etude des poissions et des reptiles du Jurassique et du Cretaceous. Direction des Travaux Geologiques Portugal. 1-46.
Osborn, 1924. Three new Theropoda, Protoceratops zone, central Mongolia. American Museum Novitates. 144, 1-12.
Nopcsa, 1928. The genera of reptiles. Palaeobiologica. 1, 163-188.
Nopcsa, 1929. Addendum "The genera of reptiles". Palaeobiologica. 2, 201.
Huene, 1932. Die fossile Reptil-Ordnung Saurischia, ihre Entwicklung und Geschichte. Monographien zur Geologie und Palaeontologie. 4(1), 361 pp.
Lapparent and Lavocat, 1955. Dinosauriens. In Piveteau (ed.). Traite de Paleontologie. Masson et Cie. 5, 785-962.
Lapparent, 1967. Les dinosaures de France. Sciences. 51, 4-19.
Ostrom, 1969. Osteology of Deinonychus antirrhopus, an unusual theropod from the Lower Cretaceous of Montana. Peabody Museum of Natural History Bulletin. 30, 1-165.
Steel, 1970. Part 14. Saurischia. Handbuch der Paläoherpetologie/Encyclopedia of Paleoherpetology. Gustav Fischer Verlag. 87 pp.
Olshevsky, 1978. The archosaurian taxa (excluding the Crocodylia). Mesozoic Meanderings. 1, 50 pp.
Galton, 1982. Elaphrosaurus, an ornithomimid dinosaur from the Upper Jurassic of North America and Africa. Paläontologische Zeitschrift. 56, 265-275.
Vadet and Rose, 1986. Catalogue commente des types et figures de dinosauriens, ichthyosauriens, sauropterygiens, pterosauriens et cheloninens du Musée d'Histoire Naturelle de Boulogne-sur-Mer. In E. Buffetaut, Rose and Vadet (eds.). Vértébrés Fossiles du Boulonnais. Mémoires de la Société Académique du Boulonnais. 1(2), 85-97.
Rose, 1987. Redecouverte d'une vertebre caudale reptilienne (Archosauriens) de status controverse et provenant des terrains jurassiques superieurs du Boulonnais. Bulletin de la Société académique du Boulonnais. 1(5), 150-153.
Buffetaut, Cuny and le Loeuff, 1991. French Dinosaurs: The best record in Europe? Modern Geology. 16(1-2), 17-42.
Buffetaut and Martin, 1993. Late Jurassic dinosaurs from the Boulonnais (northern France): A review. Revue de Paléobiologie. 7(vol. spéc.), 17-28.
Ford, 2005 online. http://www.paleofile.com/Dinosaurs/Theropods/Teinurosaurus.asp

* minor edits (see Marjanovic's comment)

And before we go, here are a couple more tidbits I've noticed in the upcoming update...

- That theropod tail preserved in Burmese amber (DIP-V-15103) described by Xing et al. (2016) was only placed as specifically as a non-pygostylian maniraptoriform.  But as the deposits are Gondwanan (e.g. Poinar, 2018), the range of potential Cenomanian theropods is better understood.  And only one group has caudal centra over three times longer than tall- unenlagiines.  I bet DIP-V-15103 is our first sample of preserved plumage in an unenlagiine, which makes you wonder if the weird alternating barb placement was a feature that evolved on Gondwana, and if so did Rahonavis' remiges exhibit it too?

- Does anyone realize both "Tralkasaurus" (Cerroni et al., 2019) and "Thanos" (Delcourt and Iori, 2018) are nomina nuda?  Neither are in an  official volume yet, though "Tralkasaurus" is scheduled for March and "Thanos" will probably make it this year if the average papers per volume of Historical Biology holds up.  "Tralkasaurus" has an empty space in its "Zoobank registration:" section, while the "Thanos" paper doesn't mention ZooBank at all, and neither  show up in ZooBank searches.  Also, one of "Thanos"' supposed autapomorphies is a deep prezygapophyseal spinodiapophyseal fossa, which does not exist in abelisaurs as it would require a spinodiapophyseal lamina.  The labeled structure seems internal, probably the centroprezygapophyseal fossa or prezygapophyseal centrodiapophyseal fossa based on CT-scanned noasaurid cervical DGM929-R.  That leaves axial pleurocoel size and distance from each other, and ventral keel strength as suggested characters.  Which can only be compared to Carnotaurus among brachyrostrans.  Hmmm...

References- Xing, McKellar, Xu, Li, Bai, Persons IV, Miyashita, Benton, Zhang, Wolfe, Yi, Tseng, Ran and Currie, 2016. A feathered dinosaur tail with primitive plumage trapped in Mid-Cretaceous amber. Current Biology. 26(24), 3352-3360.

Delcourt and Iori, 2018. A new Abelisauridae (Dinosauria: Theropoda) from São José do Rio Preto Formation, Upper Cretaceous of Brazil and comments on the Bauru Group fauna. Historical Biology. DOI: 10.1080/08912963.2018.1546700

Poinar, 2018. Burmese amber: Evidence of Gondwanan origin and Cretaceous dispersion. Historical Biology. DOI: 10.1080/08912963.2018.1446531


Cerroni, Motta, Agnolín, Aranciaga Rolando, Brissón Egli and Novas, 2019. A new abelisaurid from the Huincul Formation (Cenomanian-Turonian; Upper Cretaceous) of Río Negro province, Argentina. Journal of South American Earth Sciences. 98, 102445.

Thursday, January 2, 2020

Happy New Year 2020

Hi all.  A Theropod Database update is online, with the main additions being troodontid information and info from the Hayashibara Museum of Natural Sciences Research Bulletins 1-3.  I love these publications and wish more like them existed for other collections.  They detail the expeditions into Mongolia with exact discovery dates and field numbers for taxa like Nomingia, Elsornis and Aepyornithomimus, and tons of still undescribed specimens.  It's amazing just how many ornithomimosaurs are known from the Bayanshiree Formation for instance, when only the Garudimimus holotype has been described.  There are over twenty more including the sort-of-described "Gallimimus" "mongoliensis" specimen IGM 100/14.  So often for new taxa, especially those from the Jehol biota, no information is provided in the description as to when the specimen was discovered.  I get that many are found by non-professionals and given to museums, but at least say "the specimen was given to the museum on x-x-xx by someone who said it was excavated around year y."  Next up, halszkaraptorine and dromaeosaurid updates...

undescribed ?Gobivenator skull (HMNS coll.; field number 940801 TS-I WTB) (after Tsogtbaatar and Chinzorig, 2010).
Reference- Tsogtbaatar and Chinzorig, 2010. Fossil specimens prepared in Mongolian Paleontological Center: 2002–2008. Hayashibara Museum of Natural Sciences Research Bulletin. 3, 155-166.

Thursday, August 22, 2019

Therizinosaurs in the Lori matrix

Next up are therizinosaurs.  These are one of the best analyzed clades because I incorporated all of Zanno's (2010) characters, which is by far the largest and most recent analysis of the group until the Lori paper was published.  The topology is-


Falcarius is the most basal taxon shown of course, but Martharaptor was pruned a posteriori and can fall out anywhere in Therizinosauria outside the Alxasaurus plus Segnosaurus clade.  I tried including Thecocoelurus, but the Lori matrix is pretty terrible when it comes to scoring single vertebrae-

Thecocoelurus                       ?????????? ?????????? ?????????? ?????????? ?????????? ?????????? ?????????? ?????????? ?????????? ?????????? ???????(01)0? ?????????? ?????????? ?????????? ?????????? ?????????? ?????????? ?????????? ?????????? ?????????? ?????????? ?????????? ?????????? ?????????? ?????????? ?????????? ?????????? ?????????? ?????????? ?????????? ?????????? ?????????? ?????????? ???1?????? ?????????? ?????2???? ?????????? ?????????? ?????????? ?????????? ???????0?? ?????????? ?????????? ?????????? ?????1???? ?????????? ?????????? ?????????? ?????????? ?????????? ?????????? ?????????? ?????????? ??0??????? ?????????? ?????????? ?????????? ?????????? ?????????? ?????????? ?????????? ?????????? ?????????? ?????????? ?????????? ?????????? ?????????? ?????????? ?????????? ??????????

Jianchangosaurus fell out in the same place as its original description, with Cau's (2018) placement in Alvarezsauroidea taking 18 more steps so is very unlikely.  Mine is the only published matrix besides Senter (2011) and its derivatives to use information from the second Beipaiosaurus specimen, and incorporated photos from Zanno and the new paper on the holotype skull elements too.

Beipiaosaurus inexpectus holotype (IVPP V11559) cervical vertebra in dorsal view (courtesy of Zanno).
Zanno also provided photos of Alxasaurus and Enigmosaurus, and its depressing how much of the former is lost.  Enigmosaurus rather famously was shown by Zanno to not resemble Barsbold's original illustration that was the only reference picture known for over two decades.  Placing Enigmosaurus closer to Segnosaurus than Neimongosaurus or Erliansaurus as in Zanno's tree takes 4 more steps.  Forcing Enigmosaurus and Erlikosaurus to be sister taxa to simulate the synonymy mentioned by Barsbold (1983) takes 4 steps, so seems unlikely.  The duo moves between Nanshiungosaurus and the Segnosaurus plus Nothronychus clade.  We were the first analysis to include "Chilantaisaurus" zheziangensis, which emerged in a polytomy with Alxasaurus, Enigmosaurus and therizinosaurids.

Alxasaurus elesitaiensis holotype (IVPP V88402a) chevrons in right lateral view (natural order reversed) (courtesy of Zanno).
As was the case with Archaeornithomimus? bissektensis, we didn't include the possible chimaera of Bissekty Therizinosauria as an OTU, unlike Sues and Averianov (2015).  But if you do want to experiment with it, here's the scorings.  It emerges in a polytomy in the Suzhousaurus plus Therizinosaurus clade of therizinosaurids.  Btw, Archaeornithomimus? bissektensis does fall out most parsimoniously sister to A. asiaticus when all Bissekty material is used.

'Bissekty-Therizinosauroidea'       ????1??0?? ????1????? ?????1???? ?1???????? ?????{01}1000 ?01??????? 00???????? 2??21?0??? ???????00{123} {12}00(01)2011?? ??0???0(01)00 ??11????{12}? ?{01}0?100??? ?????????? ?1{01}?0????? ??0?0???{012}0 000(01)?010?? ?????????? ?????????? ?????0{12}?00 1?0???0??0 ??0??{01}0??? 0?1??????? ????0?1?0? {01}0?1???{01}?? ??0??????? ?????????? ?????????0 ???001??00 ??00?01?1? 10???????? ?????????1 ???0?????? ???1?????? ??????0??1 0???1(12)???? ????0???1? ????0?011? ???0????0? ???0{12}0???? ????????0? 0?0????1?? ?????????? ??010101?1 ??0?0(01)???? ?????{01}010? ???100???? ????????11 1010?????? ??0??0???? ?????????? ?????????? ??????0??? ??00?????? ?00??????? ?????????? ???????0-- -??00??010 ?????????? ??????-??? ???-010??1 0100????00 10?1?00??? ???0?00??? ?????????? ????0????? ???000???? ?0???-???? ?????????? ?????001??

Enigmosaurus mongoliensis holotype (IGM 100/84) synsacrum and ilium in ventral view (courtesy of Zanno).
Next is Therizinosauridae itself, which we refined Zhang et al.'s (2001) definition of to include type species.  Therizinosaurids first split into a clade of Erliansaurus, Neimongosaurus, Suzhousaurus and Therizinosaurus.  Forcing the former two to be outside a clade of Suzhousaurus, Therizinosaurus and the taxa below, as in Zanno's tree, takes 5 more steps.  Notably, we did not include the hindlimb IGM 100/45 in the Therizinosaurus OTU since there's no overlap and its not even particularly large.  But here's the Therizinosaurus OTU including the hindlimb.  Using this version of Therizinosaurus leaves the tree basically the same but destabilizes it somewhat in that Therizinosaurus and Erlikosaurus can now go in multiple positions within Therizinosauridae, and the Nanchao embryos are in a trichotomy with the Suzhousaurus clade and the Nothronychus clade.  Is this an indication the hindlimb produces homoplasy and so might not belong to Therizinosaurus?

Therizinosaurus                     ?????????? ?????????? ?????????? ?????????? ?????????? ?????????? ?????????? ?????????? ?????????? ?????????? ?????????? ?????????? ?????????? ????????01 0110021000 01?0001100 00001110?? ?????????? ?????????? ?????????? ???0???010 1?0000000? 0?1??1???? ?????????? ?????????? 000??0???? ??????3??1 ?????????0 ???00????? 0?1?0?1??? ?????0???? ?????????1 ?????????? ?????0???? ?????????? ?????????? 1011010101 100100??1? ????{12}?00?? 00?12110?? 101??????? 0????0?111 00?010???? ????????1? ?????????? ????100111 1101110??? ?????????? ????????1? ?1???????? ?????????1 ???0?????? ?000?????? ?????0???1 ?????????? ?????????? ?????????? ?????????? ?????0???? ??????-00? ?00-000001 0?0100??0? 10000???0{01} ?{01}?0000??0 {01}0???????? ????????00 ?00?????0- -??11-???? ?????????? ???1?0???0
Segnosaurus galbinensis paratype (IGM 100/83) cervical neural arch in right lateral view (courtesy of Zanno).
Now comes the Nanchao therizinosaur embryos, those described by Kundrat et al. inside dendroolithid eggs.  While including such young specimens might be seen as risky, my ontogenetically conservative scoring method with state N seems to have worked fine here.  They fall out where you'd expect a Santonian-Campanian therizinosaur to do so.  Following that is Nanshiungosaurus brevispinus, which Senter et al. (2012) recovered as the next most derived therizinosaur after Alxasaurus.  Forcing it into this basal position takes 4 steps.  Nanshiungosaurus? bohlini was included but pruned a posteriori since it can go anywhere in the Segnosaurus plus Nothronychus clade.  Forcing Nanshiungosaurus monophyly is just a single step longer though, while forcing bohlini to be sister to the contemporaneous Suzhousaurus takes 2 steps.

Segnosaurus itself (which Zanno also provided photos of) pairs with ex-Alectrosaurus forelimb AMNH 6368, which has only previously been analyzed by Zanno (2006) where it pairs with Erliansaurus.  Forcing that here compared to other taxa she included results in trees 3 steps longer.  Erlikosaurus groups with the Nothronychus species in a trichotomy where it can be sister to either species.  Forcing Nothronychus monophyly takes only a single step, but note that no proposed Nothronychus characters involve elements that can be compared to Erlikosaurus (humerus and pes).  Forcing Erlikosaurus to group with Therizinosaurus as in Senter et al. requires only a single step, with Erlikosaurus moving to the Therizinosaurus clade.

Next time, oviraptorosaurs...

References-  Barsbold, 1983. Carnivorous dinosaurs from the Cretaceous of Mongolia. Transactions of the Joint Soviet-Mongolian Palaeontological Expedition. 19, 117 pp.

Zhang, Xu, Sereno, Kwang and Tan, 2001. A long-necked therizinosauroid dinosaur from the Upper Cretaceous Iren Dabasu Formation of Nei Mongol, People’s Republic of China. Vertebrata PalAsiatica. 39(4), 282-290.

Zanno, 2006. The pectoral girle and forelimb of the primitive therizinosauroid Falcarius utahensis (Theropoda, Maniraptora): Analyzing evolutionary trends within Therizinosauroidea. Journal of Vertebrate Paleontology. 26(3), 636-650.

Zanno, 2010. A taxonomic and phylogenetic re-evaluation of Therizinosauria (Dinosauria: Maniraptora). Journal of Systematic Palaeontology. 8(4), 503-543.

Senter, 2011. Using creation science to demonstrate evolution 2: Morphological continuity within Dinosauria. Journal of Evolutionary Biology. 24(10), 2197-2216.


Senter, Kirkland, DeBlieux, Madsen and Toth, 2012. New dromaeosaurids (Dinosauria: Theropoda) from the Lower Cretaceous of Utah, and the evolution of the dromaeosaurid tail. PLoS ONE. 7(5), e36790.

Sues and Averianov, 2015. Therizinosauroidea (Dinosauria: Theropoda) from the Upper Cretaceous of Uzbekistan. Cretaceous Research. 59, 155-178.

Cau, 2018. The assembly of the avian body plan: A 160-million-year long process. Bollettino della Società Paleontologica Italiana. 57(1), 1-25.

Hartman, Mortimer, Wahl, Lomax, Lippincott and Lovelace, 2019. A new paravian dinosaur from the Late Jurassic of North America supports a late acquisition of avian flight. PeerJ. 7:e7247. DOI: 10.7717/peerj.7247 

Monday, August 19, 2019

Alvarezsaurs in the Lori matrix

This time our topology is-
 

I provide a new definition for Alvarezsauroidea that adds Therizinosaurus as an external specifier since I find it most parsimonious for Therizinosauria to be its sister group, and uses Alvarezsaurus as the internal specifier unlike Sereno's that uses Shuvuuia- (Alvarezsaurus calvoi < - Ornithomimus velox, Therizinosaurus cheloniformis, Passer domesticus) .  Alvarezsauroids have had a controversial phylogenetic placement, with the Lori matrix recovering them as basal maniraptorans sister to therizinosaurs.  Yet they can be outside therizinosaurs plus pennaraptorans in 3 steps, become arctometatarsalians in 4 steps (can bring therizinosaurs or not), non-maniraptoriforms in 6 steps (they bring therizinosaurs), closer to pennaraptorans than therizinosaurs in 6 steps, paravians in 11 steps (therizinosaurs move with), closer to Compsognathus than to birds in 15 steps, closer to birds than deinonychosaurs in 27 steps, and closer to Archaeopteryx and other birds than to dromaeosaurids and troodontids in 30 steps.

Fukuivenator is an odd taxon, recovered here as the basalmost alvarezsauroid.  But it can be a therizinosaurian in only two steps, and outside Maniraptoriformes in 4 steps (it emerges in Coeluridae).  One thing I don't think it is is a dromaeosaurid, as that takes 27 more steps, and getting it into Paraves or Pennaraptora requires 11 and 7 steps respectively.  Still, I wouldn't be surprised to see this taxon work its way around the base of Maniraptoriformes once an osteology comes out.

Shuvuuia deserti IGM 100/975 axial elements in ventral view and pelvis in dorsal view (courtesy AMNH).
Nqwebasaurus was recently redescribed by Sereno (2017), which I incorporated into its scorings.  Choiniere et al. (2012) recovered it in Ornithomimosauria, but note most of the characters they list to support that are also said to be present in alvarezsauroids.  Even they could place it in Alvarezsauroidea with only 4 steps.  The Lori matrix needs 6 steps to place it in Ornithomimosauria, which I think is higher partially due to it finding Pelecanimimus to be an alvarezsauroid too.  So similarities between the two like their teeth being in a common groove and maxillary teeth being confined to the anterior third of the bone are no longer ornithomimosaur-like.  As recently noted by Cerroni et al. (2019), this makes more sense biogeographically as well.  Oh, and note that the Lori matrix found Afromimus to be a ceratosaur as in that paper.  In any case, Nqwebasaurus takes 10 steps to move to Compsognathidae, and 7 steps to move sister to Pennaraptora.

As for Pelecanimimus itself, it seems plausibly alvarezsauroid if you think about it.  The skull is famously similar to Shuvuuia, the posterior tympanic recess is in the otic recess, ossified sterna are otherwise unknown for ornithomimosaurs, the long manual digit I was always out of place compared to Harpymimus, and Europe makes more sense for otherwise Gondwanan clades in the Cretaceous.  Now if only someone would release Perez-Moreno's thesis describing it in detail...

Shuvuuia deserti IGM 100/975 pectoral and forelimb elements. Note the tiny phalanx from digit II or III at the bottom (courtesy AMNH).
Patagonykus and Bonapartenykus are usually closer to parvicursorines than Alvarezsaurus and Achillesaurus, but the Lori matrix found them just outside Alvarezsauridae instead.  Interestingly, Xu et al. (2018) recovered the same results.  It takes 3 steps to move Patagonykus closer to parvicursorines, and 4 steps to join Alvarezsaurus and Patagonykus to the exclusion of parvicursorines as in Alifanov and Barsbold (2009).  Xu et al. recover these in 5 and 7 steps respectively, and the most recent version of Longrich and Currie's alvarezsaurid matrix (Lu et al., 2018) recovers a basal Patagonykus and a basal Parvicursorinae in 3 steps each.

One odd result is that the newly described Xiyunykus and Bannykus fall in Patagonykinae too.  Yet only 2 steps move them outside the Patagonykus plus Parvicursorinae clade, where they form a clade.  Another step breaks that up to place Xiyunykus more basal as in Xu et al..  Them being basal certainly fits better stratigraphically, and Xu et al. use several characters designed for alvarezsauroids that the Lori matrix didn't include yet.  Hopefully full osteologies will be published as well.

Mononykus olecranus cast YPM 56693 (of holotype) pes in plantar view (courtesy of Senter).
A patagonykine Achillesaurus as suggested by Agnolin et al. (2012) takes 7 additional steps in the Lori matrix where it instead emerges just closer to parvicursorines than Alvarezsaurus.  On the other hand, only a single step joins it with Alvarezsaurus as in Longrich and Currie (2009) and only 2 steps makes it just further from parvicursorines than Alvarezsaurus as in Xu et al. (2018).

Alnashetri is known from type hindlimb material, but now also from MPCA 377, a nearly complete specimen with interesting characters like flat and unfused sternal plates.  Makovicky et al. (2016) used this data to recover it as the sister group to Alvarezsauridae, and while the few published details left it more derived in the Lori tree, it can go to a more basal position with only two steps.  It should be interesting to compare to e.g. Bannykus once it is published.

Mononykus olecranus cast YPM 56693 (of holotype) (courtesy of Senter).
The arctometatarsal clade has a unique topology, but no other analysis has included nearly as many characters or all of these taxa, with Lu et al. omitting Albinykus and Ceratonykus among non-fragmentary specimens, and Xu et al. omitting the more recently described Qiupanykus.  Enforcing the Lori topology in Lu et al.'s matrix is only 5 steps longer, and doing so in Xu et al.'s matrix is only 6 steps longer.  On the other hand, Xu et al.'s topology is so unresolved at this level, the only difference in mine is placing the Albinykus plus Xixianykus clade basally near Albertonykus, which takes 5 steps to do in the Lori matrix.

It should be noted that Lu et al.'s illustrated topology (their Figure 3) is not their matrix's real result, as they did not fully analyze tree space.  Instead of 20 trees, there are 214 trees.  These differ in that Albertonykus, YPM 1049 and undescribed 41HIII-0104 can fall out anywhere more derived than Patagonykus, and that Parvicursor, the Tugriken Shireh taxon, Shuvuuia and Mononykus form an unresolved polytomy.  This leaves Linhenykus, Qiupanykus and Xixianykus unresolved between that polytomy and Patagonykus, which is perfectly compatible with the Lori topology.  This may also show that the small alvarezsauroid-specific matrix of Longrich and Currie is insufficient given all the new taxa described since 2009.  YPM 1049 was far too fragmentary to include (distal metatarsal III) but I tried testing undescribed Quipa specimen 41HIII-0104.  Didn't make it into the publication, but here's its scorings-

'41HIII0104'                        ?????????? ?????????? ?????????? ?????????? ?????????? ?????????? ?????????? ?????????? ?????????? ???????-?? ?????????1 ?10??????? ?????????? ?????????? ???0?????? ????1????? ???1?????{01} ?????????? ?????????? ?????????? ????????0? ????????3? ?????????? ?????????? ?????????? ?????????? ?????????1 ?????????1 1????????? 1????????? ?????????? ?????????? ?????????? ???1?????? ?????????? ?????????? ?????????? ?????????? ?????????? ?????????? ?????????? ?????????? ?????????? ?????????? ?????????? ?????????? ????????0? ?????????? ?????????? ?????????? ?????????? ?????????? ???1?????? ?????????? ?????????? ?????????? ?????????? ?????????? ?????????? ?????????? ?????????? ?????????? ?????????? ?????{123}???? ?????????? ?????????? ?????????? ?????????? ?????????? ??1???0???

Tugriken Shireh parvicursorine (IGM 100/99) vertebrae and ilia in ventral view, forelimb and fibula in lower right (courtesy AMNH).
Interestingly, Agnolin et al., Xu et al. and the Lori analysis all recovered Albinykus sister to Xixianykus outside Parvicursorinae.  Wonder if that's a real signal?  Unfortunately, the only attempt to name this clade was Agnolin et al. who also recovered Ceratonykus in there and called it Ceratonykini.  Xu et al. place Ceratonykus closer to parvicursorines, while I found it more basal than either, sister to Qiupanykus which neither of the other studies used.  Forcing Ceratonykus sister to Albonykus plus Xixianykus takes 3 more steps in the Lori matrix.  Forcing Ceratonykus sister to Mononykus as in its original description (with or without Qiupanykus) takes 5 more steps.  As stated in the paper, we were the first analysis to include Hateg tibiotarsi Bradycneme and Heptasteornis.  While the former can fall into many positions in Maniraptora, the latter was resolved as an alvarezsaurid as proposed by Naish and Dyke (2004).  Note this used only the tibiotarsus and not alvarezsaurid-like distal femur FGGUB R.1957.  A single step moves Heptasteornis to Troodontidae.

We also provide an updated definition for Parvicursorinae (Mononykus olecranus + Parvicursor remotus), like Choiniere et al.'s (2010) but using species.   One accident of our definitional and discovery history is that all these newer arctometatarsal alvarezsaurids (Xixianykus, Albertonykus, Albinykus, Linhenykus, Qiupanykus, Ceratonykus, etc.) emerge outside the originally discovered and defined Parvicursorinae.  We could really use some clade defining taxa closer to Mononykus than Patagonykus, Alvarezsaurus or Achillesaurus.  In any case, I got a lot of experience with parvicursorine specimens, examining Shuvuuia and the Tugriken Shireh specimen IGM 100/99 in person, and having photos of high quality casts of Mononykus thanks to Senter.  I found the Tugriken Shireh taxon closer to Shuvuuia, but moving it closer to Parvicursor as in Longrich and Currie is just 1 step longer.

Tugriken Shireh parvicursorine (IGM 100/99) vertebrae and ilia in dorsal view, forelimb and fibula in lower right (courtesy AMNH).
Next time, therizinosaurs...

References-  Naish and Dyke, 2004. Heptasteornis was no ornithomimid, troodontid, dromaeosaurid or owl: The first alvarezsaurid (Dinosauria: Theropoda) from Europe. Neus Jahrbuch für Geologie und Paläontologie. 7, 385-401.

Alifanov and Barsbold, 2009. Ceratonykus oculatus gen. et sp. nov., a new dinosaur (?Theropoda, Alvarezsauria) from the Late Cretaceous of Mongolia. Paleontological Journal. 43(1), 94-106.

Longrich and Currie, 2009. Albertonykus borealis, a new alvarezsaur (Dinosauria: Theropoda) from the Early Maastrichtian of Alberta, Canada: Implications for the systematics and ecology of the Alvarezsauridae. Cretaceous Research. 30(1), 239-252.

Choiniere, Xu, Clark, Forster, Guo and Han, 2010. A basal alvarezsauroid theropod from the early Late Jurassic of Xinjiang, China. Science. 327, 571-574. 

Agnolin, Powell, Novas and Kundrat, 2012. New alvarezsaurid (Dinosauria, Theropoda) from uppermost Cretaceous of north-western Patagonia with associated eggs. Cretaceous Research. 35, 33-56.

Makovicky, Apesteguia and Gianechini, 2016. A new, almost complete specimen of Alnashetri cerropoliciensis (Dinosauria: Theropoda) impacts our understanding of alvarezsauroid evolution. XXX Jornadas Argentinas de Paleontologia de Vertebrados. Libro de resumenes, 74.

Sereno, 2017. Early Cretaceous ornithomimosaurs (Dinosauria: Coelurosauria) from Africa. Ameghiniana. 54, 576-616.

Lu, Xu, Chang, Jia, Zhang, Gao, Zhang, Zhang and Ding, 2018. A new alvarezsaurid dinosaur from the Late Cretaceous Qiupa Formation of Luanchuan, Henan Province, central China. China Geology. 1, 28-35.

Xu, Choiniere, Tan, Benson, Clark, Sullivan, Zhao, Han, Ma, He, Wang, Xing and Tan, 2018. Two Early Cretaceous fossils document transitional stages in alvarezsaurian dinosaur evolution. Current Biology. 28, 1-8. DOI: 10.1016/j.cub.2018.07.057

Cerroni, Agnolin, Egli and Novas, 2019. The phylogenetic position of Afromimus tenerensis Sereno, 2017 and its paleobiogeographical implications. Journal of African Earth Sciences. DOI: 10.1016/j.jafrearsci.2019.103572

Hartman, Mortimer, Wahl, Lomax, Lippincott and Lovelace, 2019. A new paravian dinosaur from the Late Jurassic of North America supports a late acquisition of avian flight. PeerJ. 7:e7247. DOI: 10.7717/peerj.7247

Saturday, August 10, 2019

Ornithomimosaurs in the Lori matrix

Next up is Ornithomimosauria.  The Theropod Database has been updated with new ornithomimosaur info too.  The published cladogram here is-


I included the Angeac taxon as an OTU, which had very few illustrated elements at the time of scoring- the cervical, tibia and distal metatarsus with a few other reported details like the toothless dentary.  It emerged as an ornithomimosaur but since then good views of the known material have been made public and it's pretty obviously a ceratosaur similar to Limusaurus or Elaphrosaurus.  This was always an easy possibility in the matrix, as it can move to Ceratosauria in the published matrix with only two steps.  After rescoring it for the more complete remains, the Angeac  taxon emerges in Ceratosauria sister to Deltadromeus.  Here's its new scorings

????????1? ?????????? ?????????? ?????????? ?????????? 0????????? ?????????? ???2??0??? ?????????- ????--???? ??0?0??10? ???{01}??0??0 000?1?1{01}0? ???????{01}01 ?01?02{01}0?{01} ?????????? ????????11 1000?0?110 1100??{12}?00 ?1?10?1000 1??0??001? ??0??000{01}0 ???001???? ???0?????? {01}?021??0?1 ?0?110???? ?000?0{012}0?? ??{01}0???1?? ?????0?002 ??1?0?0??0 ??100?0?0? ??????11{01}1 ?????????? 1??1??{23}??? ?????????? ????-22?00 1001??0??? ?????????? 0??0011??? ?2000????? ?0?????00? ?0?000??0? ????{12}???0? ????000??? ??0-?1???? 0?1?1{01}???? ??1-?????0 ?0?????0?? ??00010?0? ?00??????? 0???????00 ???011???? ??00?????? ??0???0??0 ??0??????? ?????????? ?????????? ????0??010 ?????????? ???000-?0? ?0?-01?00? ???1?0??{01}? ??0?1????? ?????????? ??000?-?1? 00???0?{01}?? ???000???- -??00-???? ??????0??0 0???????0?

When Angeac moves in the new matrix with added taxa, we get a little change where Harpymimus is more basal and the polytomy is resolved-


Btw, I published a list of phylogenetic definitions in the supplementary material, including the first to define Ornithomimosauria on the type species- (Ornithomimus velox < - Tyrannosaurus rex, Shuvuuia deserti, Therizinosaurus cheloniformis, Oviraptor philoceratops, Troodon formosus, Passer domesticus).

Ours is one of the few published studies using the new Deinocheirus skeletons, and unlike Lee et al. (2014) I recovered it basal to garudimimids and any other ornithomimosaurs except for Hexing.  It only takes 4 steps to move with other toothless ornithomimosaurs, so that's still quite possible.  What seems implausible is it being a garudimimid, as that takes 14 steps.  The supporting evidence for that in Lee et al.'s analysis was never great, and as shown in the Sciurumimus section the scoring in Choiniere's analysis is pretty bad.

This is the first time Hexing has been in an analysis besides the ornithomimosaur-only one in its original description, which did not include Deinocheirus.  It groups with Deinocheirus, which is funny because of the size difference, but there would have to be something to fill up that ghost lineage if Deinocheirus is so basal.

Shenzhousaurus and Harpymimus are next.  Kinnareemimus takes three steps to move to Ornithomimosauria in the old matrix, but only one step in the new matrix.  It emerges in a trichotomy with Shenzhousaurus and Harpymimus. An extra step moves it to Alvarezsauroidea, so that's still pretty uncertain.

Archaeornithomimus asiaticus paratype left femur in posterior view (AMNH 21800) (Courtesy AMNH).

While I didn't recover Deinocheirus by Garudimimus, I did get Beishanlong there as in Lee et al..  Also interesting is that Archaeornithomimus groups there.  That genus is known from a whole ton more specimens than suggested by Smith and Galton (1990), which I was able to examine at the AMNH.  There are whole boxes of tibiae, and metatarsals, and phalanges, that could really use a new osteology.  Where's Archaeornithomimus bissektensis you ask?  Its holotype femur went way too many places to include, lacking a unique combination of scores.  Sues and Averianov (2015) did assign a lot of Bissekty material to the taxon, but I didn't include any of the Bissekty isolated composite taxa in case they're chimaerical.  I still scored them though, so if anyone wants to experiment, the Bissekty Ornithomimosauria is-

???????0?? ?????????? ?????????? ?????????? ?????{01}0000 ?0???????? ?????????? ?????????? ?????????? ?????????? ??011010(01)0 ?011????0? 0?0??0???? ?????????? 10{01}0?2{01}00? ?01??0??{01}1 0??1?0???? ?0?0?0?00? ?????????? ?????01000 1100210000 1100000020 ?????????? ????0????? ???2?0?1?? 0???0????? ?00??0??0? ??00?????0 ???10??00? 1?1??????? ????0???0? ????????11 ?????????? ??010????? ??????0??? ?????2???? {01}???0?0?01 ??????10?? ???0?11??? ?210?????? 1??????00? 0????0?0?1 ????????0? ??1?000??? ?????0???? ??1??{01}001? ??1??00??0 10??????10 0(01)1000?0?0 ?????0???? 0???????0? ???1?????? ??0?0??0?? ??00?????? ?????????? ?????????? ?????????? ???00??010 ??0?-????? ??????-?00 ?00-010??1 -11100??00 ???????--? ???00?00?? 0?00?????? ?00?000100 0{01}0000???- -???{01}--??? ??-?0????? ?10?100??0

Archaeornithomimus? bissektensis holotype right femur (CCMGE 726/12457) (Courtesy of Averianov).

 The "Grusimimus" specimen GIN 960910KD ends up in Garudimimidae too, despite generally being seen as a potential juvenile Harpymimus.  Joining the two takes 4 steps, so is still quite possible.  I wonder if this really is an endemic Asian clade.  Interestingly, Arkansaurus (which we were able to score based on the new description) is a basal garudimimid here, but it can move either a node outside the garudimimid plus ornithomimid clade, or to Ornithomimidae or to Tyrannosauroidea (where it ends up similar to where Suskityrannus was placed by its authors) with one step.  The Lori matrix isn't that great with pedal characters yet.

We also provide a definition for Ornithomimidae using O. velox and not dependent on the controversial Deinocheirus- (Ornithomimus velox < - Garudimimus brevipes). At the base of Ornithomimidae, we have Nedcolbertia.  While an ornithomimosaurian Nedcolbertia's been recently proposed by Brownstein (2017) and Hunt and Quinn (2018), this is the first published analysis to find the result.  That being said, only 3 steps move it outside Maniraptoriformes, where it falls out by Zuolong and megaraptorans.  Guess there was some real signal keeping it outside Tyrannoraptora in Dal Sasso and Maganuvo's (2011) TWiG analysis.  Brusatte's redescription should shed light on Nedcolbertia's anatomy, as should the description of BYU 19114 from the Cedar Mountain Formation, said to be similar by Hunt and Quinn. 

Interestingly, Ornithomimus velox does not group with Dromiceiomimus (which includes O. edmontonicus here), but is instead down by Sinornithomimus.  The only character really grouping traditional Ornithomimus species together is metacarpal I being longer than metacarpal II, which was not a character in the Lori matrix but it still takes 3 steps to combine them.  Note Claessens and Loewen (2015) in their excellent redescription just assume Ornithomimus sensu lato is monophyletic based on the metacarpal length, and I don't think anyone's actually used O. velox as its own OTU before this.  It would be funny if Sinornithomimus ended up actually being the Chinese sister taxon to OrnithomimusAepyornithomimus is sister to this pair in the published matrix, but in a trichotomy with Ornithomimus, Sinornithomimus and more derived taxa in the new version (not shown).  It wasn't resolved in its original description's analysis using the Choiniere matrix, merely more derived than Archaeornithomimus.

Next is a novel clade of Tototlmimus and "Gallimimus" "mongoliensis", the first time the latter has been included in an analysis.  Only 3 steps are needed to move it sister to Gallimimus bullatus, and Tototlmimus follows.  Tototlmimus was poorly resolved in its initial analysis based on Kobayashi characters.  Another new clade follows- Rativates plus Kaiparowitz supposed O. velox specimen MNA Pl.1762A plus "Ornithomimus" sedens, the latter based only on the holotype.  Again, Rativates has only been analyzed once before in its initial description, using Choiniere's heavily misscored matrix, while sedens and the Kaiparowitz specimen have never been analyzed before.



Ornithomimosaur coracoids in right lateral and proximal views. Top left- Beishanlong (after Makovicky et al., 2010). Bottom left- Anserimimus (after Barsbold, 1988). Top right- Sinornithomimus (after Kobayashi, 2004). Bottom right- Gallimimus (after Kobayashi, 2004). Peach dot indicates coracoid tubercle, green line indicates lateral edge of infraglenoid buttress.

Here's probably a good place to say that ornithomimosaur phylogeny has suffered a similar fate to coelurosaur phylogeny lately because everyone reuses Kobayashi's characters and scores just like how everyone reuses TWiG characters and scores.  So everyone gets an Anserimimus plus Gallimimus clade, then an American clade of Struthiomimus and 'Ornithomimus'.  But the former clade is only based on two coracoid characters, both of which are flawed.   Above on the right we have Kobayashi's (2004) figure 88 from his thesis illustrating the characters.  Top right is Sinornithomimus and bottom right is Gallimimus.  The first character is "laterally offset infraglenoid buttress of the coracoid", represented by how much the green curve protrudes downward here.  A bit more in Gallimimus, but compare to the then unknown Beishanlong coracoid in the upper left.  It has a hugely protruding process but isn't a part of the Anserimimus plus Gallimimus clade.  It's not a commonly shown perspective, but is also found in Nqwebasaurus, Allosaurus, etc..   The second character is "biceps tubercle positioned more anterior to base of posterior process", which is the peach dot in the figure.  Here note that Beishanlong also has this anteriorly positioned, but more problematically Anserimimus in the lower left does not.  Maybe the drawing's wrong, but the rest of that figure seems accurate (e.g. the manus) and detailed unlike some of the more schematic ones in Barsbold's works (e.g. Adasaurus' pelvis).  Note that the more recent Xu et al. (2011) ornithomimosaur analysis that finds the Kobayashi arrangment misscores Beishanlong for both characters.  Instead, the Lori analysis (and my previous unpublished TWiG analysis incorporating Kobayashi's and other ornithimomid-relevent characters) recovers a Struthiomimus plus Gallimimus clade and an Anserimimus plus Dromiceiomimus clade.  Forcing my pairing of these four in Xu et al.'s matrix only adds 2 steps, but getting the standard Kobayashi arrangement of them in my matrix takes 8 steps, so here I think I really might be on to something.

Tyrannoraptoran femora in lateral and/or anterior views. Top left- Xiongguanlong (after Li et al., 2010). Top right- Alioramus (after Brusatte et al., 2012). Center- Timimus (after Benson et al., 2012). Bottom left- Archaeornithomimus (courtesy AMNH). Bottom right- Garudimimus in lateral view (after Kobayashi and Barsbold, 2005) and Gallimimus in anterior view (after Osmolska et al., 1972).  Peach indicates accessory trochanter in anterior view, green outline indicates accessory trochanter in lateral view.

Also in the Struthiomimus plus Gallimimus group, we get Timimus as the sister taxon to the latter genus.  But of course Timimus was reassigned to Tyrannosauroidea by Benson et al. (2012).  So what gives?  Well, if you look at Benson et al.'s reasoning for rejecting an ornithomimosaurian identification, they say "The morphology of the accessory trochanter and the relatively anteroposteriorly narrow lesser trochanter of NMV P186303 are similar to those of derived tyrannosauroids such as Xiongguanlong and tyrannosaurids. They are unlike the anteroposteriorly broad, ‘aliform’ lesser trochanter and prominent, triangular accessory trochanter of allosauroids, ornithomimosaurs ..."  "NMV P186303 lacks several features present in all ornithomimosaurs, such as the ‘aliform’ lesser trochanter and prominent accessory trochanter. In contrast, the lesser trochanter of some tyrannosauroids is anteroposteriorly narrower, and the accessory trochanter forms a transversely thickened region, similar to the condition in T. hermani (e.g., Tyrannosaurus)."  "T. hermani also possesses a proximomedially inclined (‘elevated’) femoral head, a synapomorphy of derived tyrannosauroids (e.g., Tyrannosaurus; Xiongguanlong), that is absent in ornithomimosaurs." 

First of all, Gallimimus has an elevated femoral head too (Osmolska et al., 1972: Plate XLVII).  Not as much as most tyrannosauroids', but neither does Timimus.  Of course tyrannosauroids have always been recognized as having aliform anterior trochanters as well, so this is a matter of degree.  Their figure 19B does look anteroposteriorly narrower (~49% of total femoral width; ~49% in Xiongguanlong, ~52% in Alioramus), unlike Archaeornithomimus (~69%).  But Garudimimus' ratio is ~50%.  Also note figure 19C, also labeled as lateral view, looks broader (~64%) and no doubt had a slightly more anterior angle to the photo.  Even ignoring Garudimimus, something that depends so heavily on exact angle of perspective, especially considering taphonomy and how theropod femoral heads phylogenetically vary in their anterior angle compared to the distal end (basal forms are famously more anteromedially directed), is not great evidence in my opinion.  What about that accessory trochanter?  I agree Timimus' is more tyrannosauroid in side view, but ironically because they're larger than at least Archaeornithomimus and Gallimimus (green highlight), contra Benson et al.'s statement.  And again some ornithomimosaurs like Garudimimus have large accoessory trochanters too.  Regarding transverse width, I can't see a difference between e.g. Alioramus and Gallimimus above (peach highlight).  I certainly wouldn't say Alioramus' is thicker.  So is Timimus a tyrannosauroid or an ornithomimosaur?  I don't think the evidence is great either way, and certainly no published analysis scores for these difficult to quantify degrees of trochanter size.  Honestly, the biostratigraphy makes me think it will ultimately be some coelurosaur convergent with both.  Maybe something like Aniksosaurus, also Gondwanan Early Cretaceous with a tall and narrow anterior trochanter.

Finally, Qiupalong joins the Anserimimus plus Dromiceiomimus clade. In its description, it grouped in the American clade, but that's the same Xu et al. (2011) analysis noted above that misscores Beishanlong as lacking the supposed Anserimimus plus Gallimimus characters.

So that's the Ornithomimosauria.  I think the Lori analysis does a good job here doing one of the things it's meant to- include a ton of taxa that have either never been analyzed or were only added singly and separately to existing analyses.  Another point I like to emphasize is the hidden instability of our consensus.  You might be thinking 'well your analysis seems very poorly supported if all of these tested changes only take 3 to 4 steps each'.  Yet you can rearrange the entire tree of Xu et al.'s (2011) ornithomimosaur analysis to my topology and it just needs 5 more steps in total.  And Brusatte et al.'s (2014) tree doesn't even find resolution between Harpymimus, Beishanlong, Garudimimus, Archaeornithomimus, Sinornithomimus and the derived clade.  Overall I'd say this is the best ornithomimosaur analysis published, in taxon number, character number and robusticity of results.

Next, alvarezsauroids...

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Barsbold, 1988. A new Late Cretaceous ornithomimid from the Mongolia People’s Republic. Journal of Paleontology. 1988(1), 122-125.

Smith and Galton, 1990. Osteology of Archaeornithomimus asiaticus (Upper Cretaceous, Iren Dabasu Formation, People's Republic of China). Journal of Vertebrate Paleontology. 10(2), 255-265.

Kobayashi, 2004. Asian ornithomimosaurs. PhD thesis. Southern Methodist University. 340 pp.

Kobayashi and Barsbold, 2005. Reexamination of a primitive ornithomimosaur, Garudimimus brevipes Barsbold, 1981 (Dinosauria: Theropoda), from the Late Cretaceous of Mongolia. Canadian Journal of Earth Sciences. 42(9), 1501-1521.

Li, Norell, Gao, Smith and Makovicky, 2010. A longirostrine tyrannosauroid from the Early Cretaceous of China. Proceedings of the Royal Society B. 277(1679), 183-190.

Makovicky, Li, Gao, Lewin, Erickson and Norell, 2010. A giant ornithomimosaur from the Early Cretaceous of China. Proceedings of the Royal Society B. 277, 191-198.

Dal Sasso and Maganuco, 2011. Scipionyx samniticus (Theropoda: Compsognathidae) from the Lower Cretaceous of Italy: Osteology, ontogenetic assessment, phylogeny, soft tissue anatomy, taphonomy, and palaeobiology. Memorie della Società Italiana di Scienze Naturali e del Museo Civico di Storia Naturale di Milano. 281 pp.

Xu, Kobayashi, Lu, Lee, Liu, Tanaka, Zhang, Jia and Zhang, 2011. A new ornithomimid dinosaur with North American affinities from the Late Cretaceous Qiupa Formation in Henan Province of China. Cretaceous Research. 32(2), 213-222.

Benson, Rich, Vickers-Rich and Hall, 2012. Theropod fauna from Southern Australia indicates high polar diversity and climate-driven dinosaur provinciality. PLoS ONE. 7(5), e37122.

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Hartman, Mortimer, Wahl, Lomax, Lippincott and Lovelace, 2019. A new paravian dinosaur from the Late Jurassic of North America supports a late acquisition of avian flight. PeerJ. 7:e7247. DOI: 10.7717/peerj.7247