#koleken

Koleken harassing a Titanomachya.

The small sauropod however has an unusual defense mechanism. From glands along its neck it sprays a foul smelling liquid onto the abelisaur.

The Abelisaurids!!

Big head, teeny tiny arms, every one of em a cutie

Abelisaurus - Carnotaurus

Rajasaurus - Koleken - Rugops

here are today's #Paleostream sketches!!!

today we drew Omnidens, Thaisaurus, Koleken, and Brachytrachelopan

Late flocking doodles

Omnidens

Thaisaurus

Koleken

(Maxillae [bones in the upper jaw] of Koleken inakayali [scale bar = 5 cm], from Pol et al., 2024)

Meaning of name: Koleken = from clay and water [in Teushen, referring to the fact that the original fossil was found in claystone]; inakayali = for Inakayal [one of the last chiefs of Tehuelches]

Age: Late Cretaceous (Maastrichtian)

Where found: La Colonia Formation, Chubut, Argentina

How much is known: Partial skeleton of one individual including parts of the skull, spine, and hindlimbs.

Notes: Koleken was an abelisaurid ceratosaur, making it a close relative of genera like Carnotaurus and Aucasaurus. In fact, it is known from the same rock formation as Carnotaurus, so the two may have lived alongside one another. Like other abelisaurids, Koleken had rough patches on the top and sides of its skull that may have corresponded to a keratin covering in life, though unlike Carnotaurus, it did not have prominent horns on the top of its head.

Based on microscopic examination of its bone structure, the type specimen of Koleken was not fully grown when it died, which raises the possibility that it represents a juvenile individual of Carnotaurus. However, the describers of Koleken consider the two more likely to be distinct species, because they differ in details of the skull, vertebrae, and hindlimbs that are unlikely to have changed so dramatically during growth.

Koleken