Triradiate pelvic girdle
Encyclopedia
The Triradiate pelvic girdle is a shared feature common to archosaur
s. The pelvis
has three prongs, with an elongate pubis
and ischium. This feature first appeared in the Erythrosuchidae
, large basal
archosaurian predators of the early Triassic
period.
Archosaur
Archosaurs are a group of diapsid amniotes whose living representatives consist of modern birds and crocodilians. This group also includes all extinct non-avian dinosaurs, many extinct crocodilian relatives, and pterosaurs. Archosauria, the archosaur clade, is a crown group that includes the most...
s. The pelvis
Pelvis
In human anatomy, the pelvis is the lower part of the trunk, between the abdomen and the lower limbs .The pelvis includes several structures:...
has three prongs, with an elongate pubis
Pubis (bone)
In vertebrates, the pubic bone is the ventral and anterior of the three principal bones composing either half of the pelvis.It is covered by a layer of fat, which is covered by the mons pubis....
and ischium. This feature first appeared in the Erythrosuchidae
Erythrosuchidae
Erythrosuchidae are a family of large basal archosauromorph carnivores that lived from the later Early Triassic to the early Middle Triassic . Their fossil remains are known so far from South Africa , the Perm region of Russia, and China...
, large basal
Basal (phylogenetics)
In phylogenetics, a basal clade is the earliest clade to branch in a larger clade; it appears at the base of a cladogram.A basal group forms an outgroup to the rest of the clade, such as in the following example:...
archosaurian predators of the early Triassic
Triassic
The Triassic is a geologic period and system that extends from about 250 to 200 Mya . As the first period of the Mesozoic Era, the Triassic follows the Permian and is followed by the Jurassic. Both the start and end of the Triassic are marked by major extinction events...
period.