Whatever Happened to Euskelosaurus?

In principle, any dinosaur name considered dubious or a synonym can be brought back into use unless it is an objective junior synonym (based on the same specimen as a previous name) or suppressed by the International Commission on Zoological Nomenclature. In practice, some names are much more likely than others to rise out of the mire. For example, when was the last time you thought about Polyonax? (Is this the first time you've ever had occasion to think about Polyonax?) Then there are historical names based on questionable material that once were widely used but have now fallen completely out of favor. Think Monoclonius, Palaeoscincus, or Trachodon, long-time favorites that have staggered into obsolescence and cheap dinosaur toys.

We saw a few months back that Massospondylus really came to attention because it was the oldest name available for slender "prosauropods" of southern Africa at a time when the taxonomic mood was for lumping, not because of any other great merits. Euskelosaurus is pretty much the same story, except for more robust prosauropods. They both rose to prominence in the 1970s, just in time for the grand crop of 1980s popular science dinosaur books to make it seem like they'd always been important. One of them has survived changes in taxonomic attitudes and procedures, and one has not. For this post, let's have a look at the loser.

Euskelosaurus browni was named by Thomas Henry Huxley in 1866. Actually, it was "named" via a description of a talk he gave (not something that would count today, but acceptable then). The description, such as it is, tells us that he had fossils from the Stormberg Mountains of South Africa including most of a right femur 64.8 cm (25.5 in) long, the femur was dinosaurian, and it was similar in size to those of Iguanodon or Megalosaurus.

And it looked like this. Figure 4 from Seeley (1894).

Fortunately, Huxley submitted a short paper that came out soon after and provided more substantial information (Huxley 1867). From this we learn that Huxley received the fossils secondhand from Alfred Brown of Aliwal North (=Maletswai) via Sir R. I. Murchison. They also included a partial left femur, a metatarsal and metacarpal (actually fibula fragments per Seeley 1894), the distal ends of a tibia and fibula with astragalus, the proximal end of a tibia, fragments of a couple of large flat bones, a couple of indeterminate bones, and the articular end of a large long bone. Huxley decided that they were not all from the same taxon, and gave the name Orosaurus (speaking of obscure names; no species name) to the last bone listed. The partial right femur being the most informative piece, Huxley spent much of the article describing it and comparing it to other dinosaurian femora (which was a short list in 1867). He found it to be most like that of Megalosaurus of his three choices (Iguanodon and Scelidosaurus being the others), which is reasonable given both Euskelosaurus and Megalosaurus are saurischians. He also provided an etymology, rare in 19th-century descriptions: the genus name means "good leg lizard", in reference to the large femur (little did Huxley know some ginormous femora were just around the corner) and the species name is for Brown. In the 1867 paper Huxley spells it "brownii", which I suppose means that version ought to stand since he's the first reviser (and the original "paper" is a summary of an oral presentation, a difficult venue for distinguishing "-i" and -"ii"), but "-ii" always seems to get clipped down these days.

So far we've got a typical, respectable olde-tyme dinosaur. Then things got complicated, which, honestly, is perfectly in keeping with a typical respectable olde-tyme dinosaur. Brown did not make just one collection, he made several. A second went to Murchison but disappeared from history after that (Seeley 1894; Broom 1911; per Broom, this included limb bones and other large bones). Feeling that the specimens sent to England did not get the attention they deserved, he sent another lot to Paris (Seeley 1894); this lot was described in Fischer (1870) and included caudals, chevrons, bones of the hind foot, and a pubis (Seeley 1894). Harry Govier Seeley got another lot that he included in his 1894 publication (another chevron, more toe bones and claws, a rib fragment, and a partial maxilla and premaxilla), and an additional lot including another femur went to Vienna (von Huene 1906; Yates 2007). Brown reported that all of these bones came from the same location (Broom 1911), Barnard's Spruit in the lower Elliot Formation (Galton and Van Heerden 1998).

By now you're probably suspecting that Brown had a bonebed or, by one location, he meant a wider area than just one spot. The partial jaw illustrated by Seeley is suspiciously toothy and in fact was later referred to the late lamented Aliwalia rex (Galton 1985a; Yates 2007), which in turn was based on the Vienna femur that proved to be a specimen of the prosauropod Eucnemesaurus fortis (Yates 2007). Therefore, we've definitely got a carnivorous archosaur and at least one kind of prosauropod at Barnard's Spruit, so there is no compelling reason to assume prosauropod unity given the lack of a quarry map or other documentation. How many prosauropods did Brown collect? Cooper (1980) was of the opinion that the Vienna femur was part of the type of Euskelosaurus browni(i), but that seems rather unlikely on anatomical grounds, to put it mildly (see discussions in Van Hoepen 1920 and Galton and Van Heerden 1998). That would give us at least two, Eucnemesaurus and Euskelosaurus. (We shall set aside Huxley's Orosaurus due to its inadequacies, but it *is* interesting to observe that the idea of multiple species in Brown's material goes back to the beginning.)

Meanwhile, Euskelosaurus began acquiring specimens from other locations, starting with Seeley (1894), who chose, unfortunately, to stick more pointy carnivore jaw material in it that didn't belong (Broom 1911). (One of the great unsung advancements in paleontology was the revelation that just because some bones are in the same bonebed, they don't necessarily belong to the same thing.) Other names were also introduced, until there were about ten species rattling around the lower Elliot, none of which were known from exemplary remains. Changing perceptions of South African prosauropods can be followed in several papers, e.g., Broom (1911), Van Hoepen (1920), and Haughton (1924). Then things puttered on for a few decades because nobody was much interested in dinosaurs, certainly not in a bewildering knot of poorly known not-sauropods. By the time the '70s rolled by and interest had been rekindled, a powerful instinct to clean house was also part of the deal (see for example the reductions in hadrosaurs and ceratopsians). Euskelosaurus, by virtue of being the oldest name, was just sitting there waiting for its cue, and because it was based on such generic material, it could and did encompass just about any kind of prosauropod. Once you start stretching a name, it just gets easier to stuff more things in. To show just how overstretched and meaningless Euskelosaurus had become by the early 1980s, Cooper (1980) regarded Melanorosaurus and Riojasaurus as synonyms of Euskelosaurus, and Van Heerden (1979) suggested that Massospondylus and Euskelosaurus could be large and small species of the same genus, or Massospondylus could even be young Euskelosaurus. Euskelosaurus was, quite literally, a fauna: the Euskelosaurus range zone, taking up the lower Elliot, whereas Massospondylus defined the upper Elliot.

This diagram would have been so much simpler in 1980; the entire lower half would have just been Euskelosaurus. Figure 9 in McPhee et al. (2017). CC-BY-4.0.

Ironically enough, the "prosauropod too far" proved to be Melanorosaurus, that paragon of well-defined dinosaurs (Galton 1985b). Euskelosaurus did retain its other gains for a couple of decades until decomposing in the early 2000s with hardly an argument after the type material was pointed out as inadequate (Yates 2003, 2007; Yates and Kitching 2003). The funny thing is, though, going back through those references, there's hardly any detail on the dismissal of Euskelosaurus. I'd love to see a taxonomic autopsy, done like Regalado Fernández et al. (2023). Probably the genus doesn't get saved, but it would be interesting. But maybe that is the fate of Euskelosaurus; it picked up every prosauropod in the lower Elliot with little comparative discussion, and it disgorged them all again with limited discussion.

What exactly did happen to Euskelosaurus? It got caught with a lousy type and didn't have oodles of good specimens behind it like Massospondylus did to prop it up with a neotype. The best material came from something called Plateosaurus cullingworthi, a.k.a. Plateosauravus, so when Euskelosaurus entered the cladistic era, it was basically Plateosauravus under an assumed name. It was also Eucnemesaurus, Kholumolumo, occasionally Melanorosaurus... For now, it is in repose.

References

Broom, R. 1911. On the dinosaurs of the Stormberg, South Africa. Annals of the South African Museum 7: 291–308.

Cooper, M. R. 1980. The first record of the prosauropod dinosaur Euskelosaurus from Zimbabwe. Arnoldia Zimbabwe 9(3): 1–17.

Fischer, P. 1870. Recherches sur les reptiles fossiles de l'Afrique australe. Nouvelles Archives du Muséum d'Histoire Naturelle 6: 163–200. (plates X, XI)

Galton, P. M. 1985a. The poposaurid thecodontian Teratosaurus suevicus v. Meyer, plus referred specimens mostly based on prosauropod dinosaurs, from the Middle Stubensandstein (Upper Triassic) of Nordwürttemberg. Stuttgart Beiträge zur Naturkunde (B) 116: 1–29.

Galton, P. M. 1985b. Notes on the Melanorosauridae, a family of large prosauropod dinosaurs (Saurischia: Sauropodomorpha). Geobios 18: 671–676.

Galton, P. M., and J. Van Heerden. 1998. Anatomy of the prosauropod dinosaur Blikanasaurus cromptoni (Upper Triassic, South Africa), with notes on other tetrapods from the lower Elliot Formation. Paläontologische Zeitschrift 72:163–177.

Haughton, S. H. 1924. The fauna and stratigraphy of the Stormberg Series. Annals of the South African Museum 12: 323-497.

Huxley, T. H. 1866. [On some remains of large dinosaurian reptiles from the Stormberg Mountains, South Africa.] The Geological Magazine 3(30): 563.

Huxley, T. H. 1867. On some remains of large dinosaurian reptiles from the Stormberg Mountains, South Africa. The Quarterly Journal of the Geological Society of London 23: 1–6.

McPhee, B. W., E. M. Bordy, L. Sciscio, and J. N. Choiniere. 2017. The sauropodomorph biostratigraphy of the Elliot Formation of southern Africa: tracking the evolution of Sauropodomorpha across the Triassic–Jurassic boundary. Acta Palaeontologica Polonica 62: 441–465. doi: https://doi.org/10.4202/app.00377.2017

Regalado Fernández, O. R., H. Stöhr, B. Kästle, and I. Werneburg. 2023. Diversity and taxonomy of the Late Triassic sauropodomorphs (Saurischia, Sauropodomorpha) stored in the Palaeontological Collection of Tübingen, Germany, historically referred to Plateosaurus. European Journal of Taxonomy 913(1): 1–88. doi: https://doi.org/10.5852/ejt.2023.913.2375

Seeley, H. G. 1894. On Euskelesaurus Brownii (Huxley). Annals and Magazine of Natural History (sixth series) 14(83): 317–340.

Van Heerden, J. 1979. The morphology and taxonomy of Euskelosaurus (Reptilia: Saurischia; Late Triassic) from South Africa. Navorsinge van die Nasionale Museum 4: 21–84.

Van Hoepen, E. C. N. 1920. Contributions to the knowledge of the reptiles of the Karroo Formation. 6. Further dinosaurian material in the Transvaal Museum. Annals of the Transvaal Museum 7: 7–140.

von Huene, F. 1906. Ueber die Dinosaurier der aussereuropäischen Trias. Geologische und palæontologische Abhandlungen 8: 99–156.

Yates, A.M. 2003. A new species of the primitive dinosaur Thecodontosaurus (Saurischia: Sauropodomorpha) and its implications for the systematics of early dinosaurs. Journal of Systematic Palaeontology 1(1): 1–42.

Yates, A. M. 2007. Solving a dinosaurian puzzle: the identity of Aliwalia rex Galton. Historical Biology 19(1): 93–123.

Yates, A. M., and J. W. Kitching. 2003. The earliest known sauropod dinosaur and the first steps towards sauropod locomotion. Proceedings of the Royal Society of London B 270(1525): 1753–1758.