Avipes
The Avipes was an organism that existed in the mid Triassic period. Very little is known about this creature as the fossil evidence establishing its existence is inconclusive to offer any specific details about its size, habits and habitat or nature.
It fossils attributed to the Avipes are believed to be those of an animal belonging to clade Archosauria. Archosaurs are the common ancestors of the present day birds and crocodilians. Some of the species belonging to this clade may have been dinosaurs; or at least relatives of the dinosaurs.
Some paleontologists believe that the Avipes may have been a dinosaur belonging to sub order Theropoda. The fossils ascribed to the Avipes do bear some semblance to Theropods, but it cannot be proven unequivocally that the fossils were indeed those of a Theropod.
The Avipes may have been present on the planet some 245 to 225 million years ago, about the same time most Archosaurs and Theropods existed but this figure is plain speculation.
Antetonitrus
The holotype fossils of Antetonitrus were originally found in 1981, but were thought to be further fossils of the genus Euskelosaurus. It was not until over two decades later that they would be correctly described as a distinct genus. Antetonitrus is a very interesting sauropod dinosaur, as while it was quadrupedal (walked on four legs), the fore limbs are not as well adapted for bearing the weight of the animal as later, more advanced sauropod genera. The first digit of the fore feet, comparable to your own thumb, is still twisted and opposable against the foot. As time would go on and more advanced forms appeared, the bones grew so large for additional weight bearing support that flexible movement between the bones of the fore foot would become impossible. Therefore, as a genus, Antetonitrus is a transitional link between the mostly bipedal prosauropod dinosaurs that emerged earlier in the Triassic, and the later quadrupedal sauropods that began to become commonplace as the Jurassic went on.
Aside from the fore feet, Antetonitrus appears to have been a fairly typical sauropod that roamed around using its long neck to reach plants to feed. The skull is still not known at the time of writing, so it is still unknown if Antetonitrus had any specialised feeding adaptations that may indicate a preference towards certain plant types. The vertebrae of the holotype individual are also interesting in that the neural arches (the spiky parts of the vertebrae) are not fused with the centra (the round bit that encloses the spinal cord), which indicates that this individual was not fully grown.
The Avipes was an organism that existed in the mid Triassic period. Very little is known about this creature as the fossil evidence establishing its existence is inconclusive to offer any specific details about its size, habits and habitat or nature.
It fossils attributed to the Avipes are believed to be those of an animal belonging to clade Archosauria. Archosaurs are the common ancestors of the present day birds and crocodilians. Some of the species belonging to this clade may have been dinosaurs; or at least relatives of the dinosaurs.
Some paleontologists believe that the Avipes may have been a dinosaur belonging to sub order Theropoda. The fossils ascribed to the Avipes do bear some semblance to Theropods, but it cannot be proven unequivocally that the fossils were indeed those of a Theropod.
The Avipes may have been present on the planet some 245 to 225 million years ago, about the same time most Archosaurs and Theropods existed but this figure is plain speculation.
Antetonitrus
The holotype fossils of Antetonitrus were originally found in 1981, but were thought to be further fossils of the genus Euskelosaurus. It was not until over two decades later that they would be correctly described as a distinct genus. Antetonitrus is a very interesting sauropod dinosaur, as while it was quadrupedal (walked on four legs), the fore limbs are not as well adapted for bearing the weight of the animal as later, more advanced sauropod genera. The first digit of the fore feet, comparable to your own thumb, is still twisted and opposable against the foot. As time would go on and more advanced forms appeared, the bones grew so large for additional weight bearing support that flexible movement between the bones of the fore foot would become impossible. Therefore, as a genus, Antetonitrus is a transitional link between the mostly bipedal prosauropod dinosaurs that emerged earlier in the Triassic, and the later quadrupedal sauropods that began to become commonplace as the Jurassic went on.
Aside from the fore feet, Antetonitrus appears to have been a fairly typical sauropod that roamed around using its long neck to reach plants to feed. The skull is still not known at the time of writing, so it is still unknown if Antetonitrus had any specialised feeding adaptations that may indicate a preference towards certain plant types. The vertebrae of the holotype individual are also interesting in that the neural arches (the spiky parts of the vertebrae) are not fused with the centra (the round bit that encloses the spinal cord), which indicates that this individual was not fully grown.
No comments:
Post a Comment