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.

* 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.