"Megalosaurus" cloacinus and more - September 2021 Database Update

Hi everyone.  I realize it's been ten months since the last post, and that's because I've been prioritizing updating the Database over writing blogs.  As a compromise of sorts and to not force people to constantly check the Database updates page, I decided to try out posting when I update including features that could have made it into their own blog post.

One thing I've been doing is working my way through Skawiński et al.'s (2017) paper on Polish Triassic dinosaur reports, which in addition to unnamed fragments, also led to the creation of entries for two supposed Megalosaurus species.  silesiacus is a generic carnivorous archosauriform tooth too early to be dinosaurian, while cloacinus has been used for basically every carnivorous archosaur tooth from Rhaetian beds of Germany.  The interesting thing about the latter is that workers apparently forgot that it was based on lost teeth described by Quenstedt, not the SMNS tooth figured 47 years later by Huene.

"Zanclodon" silesiacus Jaekel, 1910
= Megalosaurus silesiacus (Jaekel, 1910) Kuhn, 1965
Early Anisian, Middle Triassic
Lower Gogolin Formation, Lower Muschelkalk, Poland
Holotype- (University of Griefswalden/Göttinger coll.; lost?) tooth (24x12x5 mm)
Referred- ?(Geological Museum of the Polish Geological Institute-National Research Institute coll.) tooth (Skawiński, Ziegler, Czepiński, Szermański, Tałanda, Surmik and Niedźwiedzki, 2017)
?(Silesian University of Technology, Faculty of Mining and Geology coll.) tooth (37 mm) (Surmik and Brachaniec, 2013)
Comments- Jaekel (1910) noted (translated) "a dinosaur tooth from the lower shell limestone of Upper Silesia, which would probably be the oldest known dinosaur tooth to date. It comes from the Chorzov strata of the lower shell limestone of Gogolin, Upper Silesia, and came to me through the kindness of engineer Fedder in Opole. The crown shown is 24 mm high, 12 mm wide and 5 mm thick, so it is quite strongly compressed and slightly curved backwards. Its edge is extremely finely serrated (Fig. 16 A). I call the form, which for the time being cannot be specified generically, Zanclodon silesiacus. The only difference between [phytosaur Mesorhinosuchus] and this tooth form lies in the fact that the former is somewhat thicker, somewhat less bent back, and that no notch can be detected on the edge."  He referred it to Megalosauridae, and Kuhn (1965) later referred it to the genus Megalosaurus.  Carrano et al. (2012) correctly noted "could be considered as Theropoda indet., but we cannot rule out the possibility that it represents a 'rauisuchian' archosaur."  Surmik and Brachaniec (2013) describe a tooth from Gogolin Quarry in which "a poor state of preservation makes it impossible to identification of the presence of edge serration, however it still shows a slightly curvature and specific both sides flattening" and identify it as seemingly archosaurian.  Skawiński et al. (2017) listed this and another tooth labeled as Megalosaurus silesiacus as other material of Zanclodon silesiacus.  The latter tooth is stated to be serrated mesially and distally with a density of 12 per 5 mm.  They describe the holotype tooth as "Probably lost" and "lost", and place all three teeth as Archosauromorpha indet..  They are more specifically referred to the Teyujagua plus archosauriform clade here given the recurvature and small serrations, as authors from Kuhn onward have noted plesiomorphic theropod teeth are difficult to distinguish from several clades of archosauriforms (e.g. erythrosuchids, euparkeriids) known from the Anisian.  The age is far too early for Megalosaurus or another neotheropod, and the presence of serrations is unlike Zanclodon, so neither genus is appropriate.  It should also be noted the three Gogolin teeth differ in shape with the Silesian University specimen less recurved and less tapered than the other two, while the Polish Geological Institute specimen is shorter than the holotype and less concave distally.  This could be positional variation, but given the lack of proposed synapomorphies could easily represent multiple taxa.
References- Jaekel, 1910. Ueber einen neuen Belodonten aus dem Buntsandstein von Bernburg. Sitzungsberichte der Gesellschaft Naturforschender Freunde zu Berlin. 5, 197-229.
Kuhn, 1965. Fossilium Catalogus 1: Animalia. Pars 109: Saurischia. Ysel Press. 94 pp.
Carrano, Benson and Sampson, 2012. The phylogeny of Tetanurae (Dinosauria: Theropoda). Journal of Systematic Palaeontology. 10(2), 211-300.
Surmik and Brachaniec, 2013. The large superpredators' teeth from Middle Triassic of Poland. Contemporary Trends in Geoscience. 2, 91-94.
Skawiński, Ziegler, Czepiński, Szermański, Tałanda, Surmik and Niedźwiedzki, 2017 (online 2016). A re-evaluation of the historical 'dinosaur' remains from the Middle-Upper Triassic of Poland. Historical Biology. 29(4), 442-472.

 

Holotype tooth of "Zanclodon" silesiacus (University of Griefswalden/Göttinger coll.; lost?) in labial (A), basal section (B) and more apical section (C) (after Jaekel, 1910).

"Megalosaurus" cloacinus Quenstedt, 1858
= Plateosaurus cloacinus (Quenstedt, 1858) Huene, 1905
= Gresslyosaurus cloacinus (Quenstedt, 1858) Huene, 1932
= Pachysaurus cloacinus (Quenstedt, 1858) Huene, 1932
Rhaetian, Late Triassic
Exter Formation, Germany
Syntypes- (lost) two teeth
Referred- ?(GPIT and SMNS coll.) many teeth (Huene, 1905)
?(SMNS 52457) tooth (~25x11x? mm) (Huene, 1905)
?(SMNS coll.) teeth (Roemer, 1870)
? seven teeth (Miller Endlich, 1870)
Norian-Rhaetian?, Late Triassic
'Lisów Breccia', Poland
?(University of Wroclaw coll.; lost) two teeth (Roemer, 1870)
Early Hettangian, Early Jurassic
Calcaire de Valognes, Manche, France
?(University of Caen coll.; destroyed) tooth (Rioult, 1978)
Comments- Quenstedt (1858) originally described (translated) "barb-shaped teeth, which are sharp and finely serrated on the concave side, but rounded and smooth on the convex side" with a large mesioapically placed wear facet that makes that edge look straight in side view.  He also figures a smaller tooth which has mesial serrations apically that transition to a rounded edge basally.  These teeth do not share any obvious synapomorphies and differ in elongation (height/FABL ~300% vs. 138%) and transverse thickness (42% vs. 75% of FABL), so may not belong to the same taxon.  Miller Endlich (1870) figured seven teeth from the type locality, stating (translated) they "are mostly flat teeth, slightly curved on one side, with fine serrations on the sharp inner edge. The convex side, the back, does not seem to be serrated, but it is not certain."  The figured teeth show a wide range of variation, with figure 13 in particular being stout and unrecurved with large serrations, similar to the Lucianosaurus paratype and similarly referrable to Archosauromorpha incertae sedis.  The other teeth have small serrations, with 14 and 18 being straight and 15-17 and 19 being recurved, with 14, 18 and 15 being progressively more transversely compressed.  As with the syntypes, these exhibit variation which could be positional or interspecific, and share no obvious characters that connect them to each other or the syntypes.  Roemer (1870) wrote (translated) "In the Stuttgart Museum I saw teeth from the bone breccia of Bebenhausen near Tubingen, which show the same fine serration of the side edges as the teeth described by Quenstedt, but are not curved in a sickle shape, but are straight. It is very likely that these latter teeth belong to the same dinosaur as the crooked teeth. With these straight teeth from Bebenhausen, the tooth shown in FIGS. 4 and 5 from the Lisów Breccia from Lubsza near Woźniki completely coincides. The double-edged tooth, which is very delicately and regularly notched at the edges, shows a more strongly curved (outer) and a less curved (inner) surface, both of which are smooth except for a very fine, irregular wrinkle. There is also a much smaller tooth of the same type from the same location."  The straight Bebenhausen teeth sound similar to Miller Endlich's figures 14 and 18, although the illustrated straight tooth from Lubsza differs from these in having an increased amount of mesiodistal expansion basally.  The Lubsza tooth also has this marked basal expansion labiolingually, and both types of root expansion are atypical of dinosaurs, suggesting this is some other type of vertebrate.  Dzik and Sulej (2007) suggested it "may have belonged to a phytosaur" without evidence but Skawiński et al. (2017) stated "phytosaur fossils have not been found in the upper Keuper strata in Silesia" and instead placed it in Archosauromorpha indet..  While this could merely mean phytosaurs were rare in that strata, phytosaur teeth don't seem to have expanded roots either (e.g. Nicrosaurus), and it could even be a fish tooth which often have these types of root expansion.  Huene (1905) listed the species as "Plateosaurus" cloacinus within Theropoda, stating it includes Rhaetian dentary "Zanclodon cambrensis".  In 1908 he places it in Plateosauridae within Theropoda and states (translated) "The originals can no longer be found. The Tübingen collection still has several teeth from Bebenhausen and Schloßlesmuehle, which can be reconciled well with [Quenstedt's] fig. 12 (l. c.), but are larger. The serrations are coarse and short, the mesial carina does not extend all the way to the base."  He illustrated a tooth in figure  274 as "From the Rhaetian Bonebed of Bebenhausen near Tübingen. Tooth in nat. Size. The tip is missing. Original in the natural history cabinet in Stuttgart."  Regarding cambrensis, Huene states "The teeth have the greatest resemblance to Plateosaurus cloacinus both in the whole shape and in the serrations. Whether it is really the same or just a very similar species, of course, cannot be decided with certainty given the scanty material", which is not explicit enough to evaluate given published details.  Huene later (1932) assigns cloacinus to Teratosauridae within Carnosauria, listed as both Pachysaurus cloacinus (pg. 6) and Gresslyosaurus cloacinus (pg. 72, 114).  Steel (1970) calls it Gresslyosaurus cloacinus within Plateosauridae.  Buffetaut et al. (1991) mentions "A tooth referred to Megalosaurus cloacinus Quenstedt, from the Lower Hettangian of the Calcaire de Valognes at Valognes (Manche), [which] has been mentioned by Rioult (1978a) as having been destroyed by an air raid on the University of Caen in 1944."  Without additional details, it can only be said that the timing suggests a neotheropod.  Carrano et al. (2012) incorrectly claimed SMNS 52457, apparently the tooth in Huene's (1908) figure 274, is "the holotype and only specimen" of cloacinus, when Huene stated it was only one of "Many teeth ... in the stone quarries of the Schoenbuch (e.g. Bebenhausen, Schloesslesmuehle), Wuerttemberg; in the university collection in Tubingen and in the natural history cabinet in Stuttgart", and that Quenstedt's originals were lost.  SMNS 52457 could be made into a neotype, but this must be done explicitly (ICZN Article 75.3) and so has not been accomplished yet.  Carrano et al. say the specimen "is a serrated, recurved tooth of the form typical for theropods. It is mesiodistally slender but does not show any diagnostic features and is therefore Theropoda indet", but other taxa with similar teeth lived in the Rhaetian (e.g. crocodylomorphs, Daemonosaurus), so is here placed in Archosauriformes indet..  Note Huene (1905, 1908) used "Plateosaurus" as a placeholder genus because until 1911 Plateosaurus was thought to have carnivorous teeth, and used "Pachysaurus" and "Gressylosaurus" in 1932 because until the 1980s more robust 'prosauropod' postcrania were still associated with carnivorous cranial elements, while Huene viewed megalosaurids as Jurassic carnosaurs.  Our modern consensus suggests a Rhaetian theropod is more likely to be coelophysoid or dilophosaur-grade than megalosaurian, but the genus is still used here as a placeholder as Megalosaurus teeth are more similar to cloacinus' syntypes and SMNS 52457 than prosauropod teeth.
References- Quenstedt, 1858. Der Jura. H. Laupp'schen. 842 pp.
Miller Endlich, 1870. Das Bonebed Württembergs. Druck Von Ludwig Friedrich Fues. 30 pp.
Roemer, 1870. Geologie von Oberschlesien. Robert Nischkowsky. 587 pp.
Huene, 1905. Uber die Trias-Dinosaurier Europas. Zeitschrift der Deutschen Geologischen Gesellschaft. 57, 345-349.
Huene, 1908. Die Dinosaurier der Europäischen Triasformation mit berücksichtigung der Ausseuropäischen vorkommnisse. Geologische und Palaeontologische Abhandlungen. Supplement 1(1), 1-419.
Huene, 1932. Die fossile Reptil-Ordnung Saurischia, ihre entwicklung und geschichte. Monographien zur Geologia und Palaeontologie. 1, 1-362.
Steel, 1970. Part 14. Saurischia. Handbuch der Paläoherpetologie. Gustav Fischer Verlag. 1-87.
Rioult, 1978. Inventaire des dinosauriens mésozoïques de Normandie. Ecosystèmes continentaux mésozoiques de Normandie (Livret-guide). Université de Caen. 26-29.
Buffetaut, Cuny and le Loeuff, 1991. French dinosaurs: The best record in Europe? Modern Geology. 16, 17-42.
Dzik and Sulej, 2007. A review of the early Late Triassic Krasiejów biota from Silesia, Poland. Palaeontologia Polonica. 64, 1-27.
Carrano, Benson and Sampson, 2012. The phylogeny of Tetanurae (Dinosauria: Theropoda). Journal of Systematic Palaeontology. 10(2), 211-300.
Skawiński, Ziegler, Czepiński, Szermański, Tałanda, Surmik and Niedźwiedzki, 2017 (online 2016). A re-evaluation of the historical 'dinosaur' remains from the Middle-Upper Triassic of Poland. Historical Biology. 29(4), 442-472.

Syntype teeth of "Megalosaurus" cloacinus (lost) in side and sectional views (after Quenstedt, 1858).

Other named specimens from the paper include the archosauromorph femur Zanclodon? "antiquus" based on a museum label, and neotheropod fibula Velocipes.  The latter was hilariously assigned to "Vertebrata, nomen dubium" by Rauhut and Hungerbuhler (2000), which is an example of a modern classification philosophy I dislike.  Nesbitt et al. (2007) is another egregious example, where a small subset of phylogenetically useful features are checked for, then a specimen is just thrown into whatever clade those features can narrow it to indet..  As opposed to then asking what differences exist between members of that clade and checking the specimen for them, like what Ezcurra and Brusatte (2011) did for Camposaurus.  I bet if someone did an in depth study, we would find differences between shuvosaurid and coelophysoid dorsals and caudals and thus be able to narrow down a lot of specimens currently sitting in Archosauria indet. for instance.

The other thing about Skawiński et al.'s Velocipes discussion that didn't fit into its Database entry is that they claim "It is worth noting that there is great variation in shape of proximal end of fibula of Coelophysis bauri in proximal view – some specimens are more rectangular and others more triangular, some bear flat medial surface, while in others it is strongly concave (compare von Huene 1915, fig. 51; Hutchinson 2002, fig. 2c; Spielmann et al. 2007a, fig. 6 H)."  But this is comparing Arroyo Seco AMNH 2745 with Padian's unnamed Petrified Forest coelophysoid (Ezcurra et al., 2021) with the Snyder Quarry coelophysoid, that are not necessarily conspecific.

Another set of specimens I've been adding/updating over the past several months are Triassic American records, with Arizona and the few bits from Utah complete, I'm currently getting through Texas.  That included Camp's material such as Spinosuchus (that is seemingly a Trilophosaurus species), and revising the Protoavis entry.  There's a lot of new detail in the latter such as the braincase being compatable with what we now know of non-averostran theropods, the skull roof matching Megalancosaurus, Paul's herrerasaurian characters no longer making sense, the coelophysoid proximal femur being robust and thus probably not juvenile, and commentary on the Kirkpatrick Quarry materials.

Protoavis texensis holotype proximal femur (TTU-P9200; top) in anterior view (after Chatterjee, 1991) compared to "Megapnosaurus" kayentakatae holotype (MNA.V.2623; bottom) (after Rowe, 1989). Note the muscle scars in the former typical of robust coelophysoids.

Speaking of coelophysoids, I finally gave up the battle for Bakker's original Neotheropoda concept and changed everything to the current consensus usages of Neotheropoda and Averostra.  Similarly, dilophosaurs are now closer to averostrans, but I note that this isn't as well supported as the consensus would have you believe, with Cau's matrix in the Saltriovenator paper changing to coelophysoid Dilophosaurus in only two steps and Nesbitt's matrix as altered by Ezcurra (and partially corrected by myself) needing only three steps.  However, Wang et al. (2016) needs a whopping eighteen more steps to place Dilophosaurus in Coelophysoidea, so that would be interesting to compare to Tykoski's (2005) thesis that took twenty additional steps to place Dilophosaurus closer to averostrans.  As part of the coelophysoid revision, Sarcosaurus was updated after Ezcurra et al. (2021).

New abelisaurid Kurupi was added.  An upcoming goal is to change Abelisauridae to the stem (away from Noasaurus and Ceratosaurus), and probably move Noasauridae outside Neoceratosauria.

New tetanurines are Ulughbegsaurus and "Cryptotyrannus", which had previously been referenced as both an ornithomimosaur and tyrannosauroid in the site.  I started to sort out and correct the eastern United States records for those groups now that I have the references instead of relying on Ford's list like I did for much of the original Tyrannosauroidea page, but there's more work to be done in that department.

I also added new unenlagiines Ypupiara and "Lopasaurus".  I found a quote in Bertini et al. (1993) seemingly referring to the latter in part- "tibia, a femur and metatarsals (all in the DNPM, Rio de Jineiro) which Price believed included at least two new genera and families [of coelurosaurs]." Intriguingly they also mention "a partial toothless dentary (with alveoli but lacking teeth) of a coelurosaur from Loc. 99" which sounds like Ypupiara, but unlike the latter is from a different locality than "Lopasaurus".

Finally, we have new birds that were added to the cladograms but not given entries yet.  Youornis is uncontroversial, but Yuanchuavis looks to just be another Pengornis but with typically dimorphic elongate retrices unlike the 'Chiappeavis' specimen.  Wasaibpanchi is a Malkani taxon that I don't think is identifiable as theropodan or as teeth from available photos, let alone as a valid taxon of enantiornithine.  But that requires going over Malkani's new 2021 paper, and the only thing I've incorporated from that so far is changing which sauropod taxa are valid and listing his new sauropod taxonomic groups and definitions.

See you in a month.

Additional References-  Rowe, 1989. A new species of the theropod dinosaur Syntarsus from the Early Jurassic Kayenta Formation of Arizona. Journal of Vertebrate Paleontology. 9(2), 125-136.

Chatterjee, 1991. Cranial anatomy and relationships of a new Triassic bird from Texas. Philosophical Transactions of the Royal Society of London Series B. 332(1265), 277-342.

Bertini, Marshall, Gayet and Brito, 1993. Vertebrate faunas from the Adamantina and Marília formations (Upper Bauru Group, Late Cretaceous, Brazil) in their stratigraphic and paleobiogeographic context. Neues Jahrbuch für Geologie und Paläontologie Abhandlungen. 188(1), 71-101.

Rauhut and Hungerbuhler, 2000. A review of European Triassic theropods. Gaia 15, 75-88.

Tykoski, 2005. Anatomy, ontogeny and phylogeny of coelophysoid theropods. PhD Dissertation. University of Texas at Austin. 553 pp.

Nesbitt, Irmis and Parker, 2007. A critical re-evaluation of the Late Triassic dinosaur taxa of North America. Journal of Systematic Palaeontology. 5(2), 209-243. 

Ezcurra and Brusatte, 2011. Taxonomic and phylogenetic reassessment of the early neotheropod dinosaur Camposaurus arizonensis from the Late Triassic of North America. Palaeontology. 54(4), 763-772.

Wang, Stiegler, Amiot, Wang, Du, Clark and Xu, 2016. Extreme ontogenetic changes in a ceratosaurian theropod. Current Biology. 27(1), 144-148.

Ezcurra, Marsh, Irmis and Nesbitt, 2021. A revision of coelophysoid theropod specimens from Petrified Forest National Park, Arizona (U.S.A.), reveals a new species from the Upper Triassic Chinle Formation. 34 Jornadas Argentinas de Paleontologia de Vertebrados, Libro de Resumenes. R16.