Telmatosaurus

Telmatosaurus was a primitive hadrosauroid dinosaur that inhabited the ancient Hateg Island of Romania at the very end of the Cretaceous. It is one of the classic examples of insular dwarfism among dinosaurs: while most Late Cretaceous duck-billed relatives reached eight to twelve metres, Telmatosaurus reached only around five metres in length and weighed roughly as much as a modern horse. Its small size allowed it to thrive within the limited land area and reduced food resources of an isolated subtropical island. It fed on low to mid-height vegetation using batteries of shearing teeth. Known from several skulls and partial skeletons, Telmatosaurus also boasts paleopathological interest, including a juvenile jaw bone displaying a prominent non-cancerous facial tumour.

One fossil skull preserves evidence of an ameloblastoma, a benign tumour rarely identified in dinosaurs.

Where and when

Telmatosaurus lived in the Late Cretaceous, from 70.6 to 66 million years ago (Maastrichtian age). Its remains come from Romania, in the Sânpetru Formation.

The numbers

Length 4.8 m (estimates run from 4.5 to 5 m). Mass about 570 kg. Hip height about 1.5 m. That is 2.8 human-lengths, or 0.43 of a double-decker bus. These are estimates from partial skeleton; fields marked estimated by the site are length, mass, hip height.

Compare Telmatosaurus with a bus Place on the timeline