A New Ankylosaur from Spain

A Spanish coal mine has yielded thousands of paleontological specimens, among them two individuals of a newly discovered nodosaurid ankylosaur described in a PLOS ONE article yesterday: Europelta carbonensis.

Figure 33 showing reconstruction of E. carbonensis from Kirkland, et al. (2013).

As an ankylosaur, Europelta was heavily armored with bony plates.  Indeed, the paper’s authors describe “an abundance of dermal armor” recovered from the sites of both individual specimens — albeit in such disarray that it’s impossible to reliably reconstruct just how the armor would have looked.  The armor that was recovered ranges from large osteodermal spikes and plates to small, knobby “ossicles.” In addition to armor, Europelta had two sets of facial horns — one below and one behind its eyes.

As a nodosaurid, Europelta had no tail club and a relatively long and narrow head.  To illustrate the head-shape differences among ankylosaurs, compare Europelta, whose head measured about 370 mm long and 200-300 mm wide to, say, Euoplocephalus, whose very broad head measured [pdf] about 330 mm long and 380 mm wide.  Despite its heavy armor, then, Europelta was perhaps more graceful in appearance than some of its cousins.

Horns and bony plates aside, Europelta apparently gives us a better date for the effective division of the supercontinent Laurasia into today’s Europe and North America.  The thinking goes that nodosaurids like the newly discovered Europelta and its North American cousin Sauropelta simultaneously sprung up in Europe and North America, respectively, about 110 million years ago.  This was probably the result of geographic connection, not random chance.  And both types of nodosaurids displaced the same type of dinosaur too — polacanthids.  Some paleontologists had thought that rising sea levels might have isolated Europe and North America from one another about 125 million years ago; Europelta provides striking evidence that this separation might have been millions of years more recent.  Pretty cool.

Finally, here’s one thing I love about reading primary scientific literature.  You sometimes get details like this;

The bonebed was located many tens of meters underground prior to strip mining operations in the Santa María coal mine. …By the end of 2012, an area of approximately 25 ha had been investigated and the areal distributions of 101 vertebrate concentrations were documented; 33 of these consisted of associated dinosaur skeletons (mostly iguanodonts) and 68 consisted of other vertebrate remains (mostly turtles and crocodilians). During this stage of the project, numerous dinosaurs (ornithischian elements and associated skeletons, and saurischian teeth), two types of turtle, crocodilians, fish (both ostheicthyians and selachiens), coprolites, molluscs (freshwater bivalves and gastropods), arthropods (ostracods), and abundant plant remains (logs, plant fragments, palynomorphs, and amber) have been excavated.

The bonebed designated AR-1 contains more than 5000 identifiable vertebrate specimens …

It’s too easy to think of strange creatures like Europelta in isolation.  Or perhaps we imagine Europelta battling some other charismatic megafauna like the smallish theropod Genusaurus, which apparently also existed in Europe around 110 million years ago [pdf].  But details like those in the excerpt above remind us that way back then there were complete ecosystems comprising many interconnected parts: dinosaurs, turtles, crocodiles, fish, molluscs, bugs, trees, other plants and their pollen or spores — and the ancient animalian droppings that have fossilized into coprolites.

(References to coal mining, though, mandate that I include this last statement: strip-mining for coal is nasty.  Check out this aerial view of the mine where Europelta was discovered.)

Reference:

Kirkland JI, Alcalá L, Loewen MA, Espílez E, Mampel L, et al. (2013) The Basal Nodosaurid Ankylosaur Europelta carbonensis n. gen., n. sp. from the Lower Cretaceous (Lower Albian) Escucha Formation of Northeastern Spain. PLoS ONE 8(12): e80405. doi:10.1371/journal.pone.0080405

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