| Thalassodromeus Temporal range: Early Cretaceous, 108 Ma |
|
|---|---|
| Life restoration | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Reptilia |
| Order: | †Pterosauria |
| Suborder: | †Pterodactyloidea |
| clade: | †Neoazhdarchia |
| Family: | †Thalassodromidae |
| Genus: | †Thalassodromeus |
| Species: | †T. sethi |
| Binomial name | |
| Thalassodromeus sethi Kellner & Campos, 2002 |
|
Thalassodromeus was a large pterodactyloid pterosaur found in northeastern Brazil.
The genus was named in 2002 by Alexander Kellner and Diogenes de Almeida Campos. The type species is Thalassodromeus sethi. The genus name is derived from Greek thalasse, "sea" and dromaios, "runner", in reference to its presumed life style as a skimmer. The specific name refers to the Egyptian god Seth because of the similarity in head form. In 2006 André Jacques Veldmeijer suggested Kellner had confused Seth with the god Amun whose crown shows a remarkable resemblance with the Thalassodromeus head crest.[1]
The genus is based on holotype DGM 1476-R, a damaged partial skull, found in the Santana Formation. Thalassodromeus lived in the Early Cretaceous, roughly 108 million years ago. It shared the skies with its smaller cousin Tapejara. It is particularly notable for its immense head crest, beginning at the tip of the snout and ending far behind the braincase, which accounts for seventy-five percent of the surface of its 1.42 metre long skull. The jaws were pointed and toothless. It had a wing span of roughly 4.5 metres.[2] The function of the crest is unknown, but it may have been used for sexual display, species recognition, or thermoregulation. A lower jaw fragment referred to Thalassodromeus, DGM 1476-M, indicates a larger exemplar with a wingspan of 5.3 metres. Another jaw fragment, SAO 251093, was unofficially suggested to be a new species, "Thalassodromeus oberli" (referring to the Urbs Oberli collection), by Veldmeijer, but he later reversed this opinion and referred the specimen to T. sethi.[3]
Thalassodromeus was believed by Kellner to have fed in a similar way to modern skimmers; trailing its lower jaw in the water while it flew. However, later research on its jaw and neck anatomy suggested that for this and other larger pterosaurs it would not be feasible to skim because of the drag: the energy expenditure would be too high.[4]
Kellner assigned Thalassodromeus to the Tapejaridae. Other analyses however, showed that it was, joined with Tupuxuara in a Thalassodrominae, more closely related to the Azhdarchidae.