Organisms in the dinosauria clade are defined by a perforate acetabulum, which can be thought of as a "hip-socket". The perforate acetabulum is a cup-shaped opening on each side of the pelvic girdle formed where the ischium, ilium, and pubis all …

In the literature, the acetabula containing the foramina of the first and second types are not distinguished from each other and are usually designated as partially perforated acetabula. The acetabular cavity commonly designated as a completely perforated or open acetabulum contains the foramen which we refer to as the third type.

One important dinosaurian synapomorphy is the perforate acetabulum, simply a "hip bone" (actually three connected bones, together called the pelvis) with a hole in the center where the head of the femur ("thigh bone") sits. This construction of the hip joint makes an erect stance (hindlimbs located directly beneath the body) necessary — like ...

2000年7月1日 · We performed comparative and experimental analyses, focusing on inter-tissue interaction during embryogenesis, and found that the avian perforated acetabulum develops via a secondary loss of ...

2023年12月27日 · Many modern birds have a mainly open acetabulum, but in others, the walls of the basin are partially ringed by thin bone covered by a fibrous sheet. The pit of the acetabulum is perforated by the foramen acetabuli at the confluence of the ilium, ischium, and pubis, located near the center of the basin.

2018年10月17日 · The perforated acetabulum has long attracted scientific attention as one of the traits suggesting a close relationship between dinosaurs and extant birds and as one of the most iconic synapomorphies of dinosaurs [36–40].

2018年10月18日 · the open acetabulum develops as a semi-perforation (slight erosion of the inner wall) in PVL 4597 (Fig. 1), close to the last common ancestor of all archosaurs in the large reptile tree (LRT, 1308 taxa). It closes in all crocs (except Terrestrisuchus and Trialestes). It opens more (but not completely) in basal dinos.

2023年11月2日 · That birds are maniraptoran theropod dinosaurs is now considered an evolutionary consensus. An “open” (i.e., completely, or substantially perforate) acetabulum is considered an important...

2022年9月7日 · It seems that in the past, the perforated acetabulum was often used as a defining characteristic of dinosaurs (synapomorphy). Many resources/museums (!) still list this as criteria for identification. But I recently was told this is not true …

2020年10月9日 · Key Points: •There is a shift towards obligate bipedalism, parasagittal (upright) posture, digitigrade stance, a grasping manus, and a perforate (open) acetabulum on the lineage up to Dinosauria. •Dinosauria is comprised of three major clades: Ornithischia, Sauropodomorpha, and Theropoda.