Thalassodromeus
Encyclopedia
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.
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. 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.
Thalassodromeus was believed by Kellner to have fed in a similar way to modern skimmer
s; 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.
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
.
Pterodactyloidea
Pterodactyloidea forms one of the two suborders of pterosaurs , and contains the most derived members of this group of flying reptiles...
pterosaur
Pterosaur
Pterosaurs were flying reptiles of the clade or order Pterosauria. They existed from the late Triassic to the end of the Cretaceous Period . Pterosaurs are the earliest vertebrates known to have evolved powered flight...
found in northeastern Brazil
Brazil
Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...
.
The genus was named in 2002 by Alexander Kellner
Alexander Kellner
Alexander Wilhelm Armin Kellner is a Liechtensteinian/Brazilian paleontologist, a leading expert in the field of the study of pterosaurs....
and Diogenes de Almeida Campos. The type species
Type species
In biological nomenclature, a type species is both a concept and a practical system which is used in the classification and nomenclature of animals and plants. The value of a "type species" lies in the fact that it makes clear what is meant by a particular genus name. A type species is the 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
Set (mythology)
Set was in Ancient Egyptian religion, a god of the desert, storms, and foreigners. In later myths he was also the god of darkness, and chaos...
because of the similarity in head form. In 2006 André Jacques Veldmeijer suggested Kellner had confused Seth with the god Amun
Amun
Amun, reconstructed Egyptian Yamānu , was a god in Egyptian mythology who in the form of Amun-Ra became the focus of the most complex system of theology in Ancient Egypt...
whose crown shows a remarkable resemblance with the Thalassodromeus head crest.
The genus is based on holotype
Holotype
A holotype is a single physical example of an organism, known to have been used when the species was formally described. It is either the single such physical example or one of several such, but explicitly designated as the holotype...
DGM 1476-R, a damaged partial skull, found in the Santana Formation
Santana Formation
The Santana Formation is a geologic Lagerstätte in northeastern Brazil's Araripe Basin where the states of Pernambuco, Piauí and Ceará come together. The geological formation, named after the village of Santana do Cariri, lies at the base of the Araripe Plateau...
. Thalassodromeus lived in the Early Cretaceous
Early Cretaceous
The Early Cretaceous or the Lower Cretaceous , is the earlier or lower of the two major divisions of the 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. The function of the crest is unknown, but it may have been used for sexual display, species recognition, or thermoregulation
Thermoregulation
Thermoregulation is the ability of an organism to keep its body temperature within certain boundaries, even when the surrounding temperature is very different...
. 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.
Thalassodromeus was believed by Kellner to have fed in a similar way to modern skimmer
Skimmer
The Skimmers, Rynchopidae, are a small family of tern-like birds in the order Charadriiformes, which also includes the waders, gulls and auks. The family comprises three species found in South Asia, Africa, and the Americas....
s; 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.
Kellner assigned Thalassodromeus to the Tapejaridae
Tapejaridae
Tapejaridae are a family of pterodactyloid pterosaurs from the early Cretaceous period. Members are currently known from Brazil and China, where the most primitive genera are found, indicating that the family has an Asian origin....
. Other analyses however, showed that it was, joined with Tupuxuara
Tupuxuara
Tupuxuara is a genus of large, crested, toothless pterodactyloid pterosaur.The genus was in 1988 named and described by Alexander Kellner and Diogenes de Almeida Campos. The type species is Tupuxuara longicristatus. The genus name refers to a familiar spirit from the mythology of the Tupi...
in a Thalassodrominae, more closely related to the Azhdarchidae
Azhdarchidae
Azhdarchidae is a family of pterosaurs known primarily from the late Cretaceous Period, though an isolated vertebrae apparently from an azhdarchid is known from the early Cretaceous as well...
.
External links
- National Geographic story on Thalassodromeus http://news.nationalgeographic.com/news/2002/07/0718_020718_pterosaur.html