Macrocnemus is an extinct genus of archosauromorph reptile known from the Middle Triassic (Late Anisian to Ladinian) of Europe and China. Macrocnemus is a member of the Tanystropheidae family and includes three species. Macrocnemus bassanii, the first species to be named and described, is known from the Besano Formation and adjacent paleontological sites in the Italian and Swiss Alps. Macrocnemus fuyuanensis, on the other hand, is known from the Zhuganpo Formation in southern China. A third species, Macrocnemus obristi, is known from the Prosanto Formation of Switzerland and is characterized b
Macrocnemus is an extinct genus of archosauromorph reptile known from the Middle Triassic (Late Anisian to Ladinian) of Europe and China. Macrocnemus is a member of the Tanystropheidae family and includes three species. Macrocnemus bassanii, the first species to be named and described, is known from the Besano Formation and adjacent paleontological sites in the Italian and Swiss Alps. Macrocnemus fuyuanensis, on the other hand, is known from the Zhuganpo Formation in southern China. A third species, Macrocnemus obristi, is known from the Prosanto Formation of Switzerland and is characterized by gracile limbs. The name Macrocnemus is Greek for "long tibia".
==Description== thumb|left|Life restoration of Macrocnemus bassanii|244x244px Macrocnemus is known from multiple specimens, most belonging to M. bassanii. It is a small reptile measuring long. Macrocnemus possessed at least 52 or 53 caudal vertebrae. Like many other early archosauromorphs, Macrocnemus had a small and low head on the end of a thin neck containing vertebrae with low neural spines and long cervical ribs. Many archosauromorphs with these features have been grouped within the order Protorosauria, although it is debatable whether this order is valid. Features that are common to most "protorosaurs" like Macrocnemus include the ankle having a hooked fifth metatarsal attached to elongated limb elements, with tarsal elements with well-ossified proximal and distal ends. Unlike in Tanystropheus, digit V of the proximal phalanx of Macrocnemus is shorter than the other digits.
Discovered by embedding cosine similarity (sentence-transformers MiniLM, 384-dim).