Crassigyrinus

Crassigyrinus
Crassigyrinus scoticus
Temporal occurrence
Lower carbon
346.7 to 330.9 million years
Locations
Scotland
Systematics
Chordates (chordata) Vertebrates (vertebrata) Jaw mouths (Gnathostomata) Land vertebrates (Tetrapoda) Crassigyrinidae Crassigyrinus
Scientific name
Crassigyrinidae
Watson , 1926
Scientific name
Crassigyrinus
Welles , 1954

Crassigyrinus scoticus was an early land vertebrate (Tetrapoda) from the Carboniferous (late Mississippian and early Pennsylvania ) of Scotland . A complete skeleton except for the tail, two skulls and several isolated lower jaws were found of him.

features

Crassigyrinus reached a total length of about 120 cm, of which the large skull made 30 cm. This made it very large for early terrestrial vertebrates. Its proportionally very short front legs are characteristic. This suggests that it was mainly in the water and found it difficult to move around on land. The hind feet were probably sufficiently developed to be used for locomotion in the water. From his strong jaw, the structure of his teeth and his height, it can be concluded that he was a top predator . The strikingly large orbit suggests relatively large eyes, perhaps an adaptation to hunting in the dark or in murky or deep waters. Parts of the vertebrae ( pleurocentra ), raven bones , shoulder blades , pubic bones , carpal bones and tarsal bones cannot be detected in fossil form and were therefore probably formed from cartilage . The skull of Crassigyrinus is well known. The clear demarcation of the roof of the skull from the cheeks resembles the structure of the skull of the Anthracosauria . In the connective tissue bones on the back of the skullcap, parallels to the meat- fin fish Eusthenopteron and Panderichthys can also be seen .

Systematics

Crassigyrinus is the only member of the Crassigyrinidae family , which is an isolated side branch of the early terrestrial vertebrates. The anatomical features of Crassigyrinus are a mosaic form of features of early terrestrial vertebrates and unique autapomorphies of the Crassiygyrinidae. Today it is mostly seen as an original land vertebrate, which has its position directly behind the first Devonian tetrapods such as Acanthostega , Ichthyostega , Hynerpeton and Tulerpeton .

swell

1. ^ ^{A b} Robert L. Carroll (2009): The rise of amphibians - 365 million years of evolution , pp. 93-97. Johns Hopkins University Press, Baltimore. ISBN 0-8018-9140-X

Web links

Commons : Crassigyrinus  - collection of images, videos and audio files

• Palaeos: Crassigyrinus