thumb|Pigeon skeleton. Number 8 indicates both left and right tarsometatarsus The tarsometatarsus (tarsus singular, tarsi plural) is a bone that is only found in the lower leg of birds and some non-avian dinosaurs. It is formed from the fusion of several bird bones found in other types of animals, and homologous to the mammalian tarsus (ankle bones) and metatarsal bones (foot). Despite this, the tarsometatarsus of flying types is often referred to as just the shank, tarsus or metatarsus.
thumb|Pigeon skeleton. Number 8 indicates both left and right tarsometatarsus The tarsometatarsus (tarsus singular, tarsi plural) is a bone that is only found in the lower leg of birds and some non-avian dinosaurs. It is formed from the fusion of several bird bones found in other types of animals, and homologous to the mammalian tarsus (ankle bones) and metatarsal bones (foot). Despite this, the tarsometatarsus of flying types is often referred to as just the shank, tarsus or metatarsus.
Tarsometatarsal fusion occurred in several ways and extents throughout bird evolution. Particularly, in Neornithes (modern birds), although the bones are joined along their entire length, the fusion is most thorough at the distal (metatarsal) end. In the Enantiornithes, a group of Mesozoic avialans, the fusion was complete at the proximal (tarsal) end, but the distal metatarsi were still partially distinct.
Discovered by embedding cosine similarity (sentence-transformers MiniLM, 384-dim).