Lutungutali
| Lutungutali Temporal range: ?Middle Triassic, ?
| |
|---|---|
| |
| Holotype ilium with a scale bar | |
Scientific classification 
| |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Family: | †Silesauridae |
| Clade: | †Sulcimentisauria |
| Genus: | †Lutungutali Peecook et al., 2013 |
| Type species | |
| †Lutungutali sitwensis Peecook et al., 2013
| |
Lutungutali (meaning "high hip" in the
dinosauriform from the Middle Triassic of Zambia. The single type species of the genus is Lutungutali sitwensis. Lutungutali was named in 2013 and described from a fossil specimen, holotype NHCC LB32, including hip bones and tail vertebrae. The specimen was collected in 2009 from the upper Ntawere Formation, which dates to the Anisian stage of the Middle Triassic. Lutungutali is the first known silesaurid from Zambia and, along with the Tanzanian silesaurid Asilisaurus and dinosauriform Nyasasaurus, the oldest bird-line archosaur known from body fossils (i.e. parts of the skeleton).[1]
Description
Lutungutali is known from parts of its
synapomorphies
) with other early dinosauriforms:
- A small area over which the pubis and ischium bones of the hip connect.
- A depression or fossa on the ischium where it connects with the pubis and ilium.
- The length of the ischium exceeding the length of the iliac bladeacross the top of the hip.
Lutungutali also shares two synapomorphies with the clade or evolutionary grouping containing silesaurids and dinosaurs:
- A crest of bone extending upward from the supraacetabular crest (a bony ridge above the acetabulum or hip socket) that joins with the preacetabular process, the forward-most projection of the iliac blade.
- A lengthy connection between the two pairs of ischia, except for a division of the two bones near their connection with the rest of the hip.
In addition, it shares two synapomorphies with other silesaurids:
- A straight lower margin of the hip socket on the ilium (more basal dinosauriforms have a convex margin, and dinosaurs have a concave margin).
- The lack of a ridge of bone behind the hip socket called the antitrochanter.
Lutungutali has one unique feature or autapomorphy that distinguishes it from all other dinosauriforms: an iliac blade that is taller than the portion of the ilium that forms the hip socket. This feature is references in its name, which means "high hip" in the Bemba Language.[1]
Phylogeny and evolutionary significance
Lutungutali belongs to Silesauridae, a
Manda Beds of Tanzania, yet it was found to be a more basal silesaurid. Below is a cladogram from the analysis:[1]
Archosauria
|
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||
Lutungutali and Asilisaurus are the two oldest known members of
derived members of Avemetatarsalia, their presence in the Anisian stage of the Middle Triassic suggests that avemetatarsalians underwent a rapid diversification at a time in their evolutionary history that was earlier than previously thought.[1]
References
- ^ .