|Named By:||Zhao LiinJun, Liu Jun, Li Chun & He Tao in 2013|
|Time Period:||Late Triassic, Carnian|
|Location:||China, Guizhou Province - Xiaowa Formation|
|Size:||3.64 meters long for the holotype|
|Fossil(s):||One individual that is represented by a skull and almost complete post cranial skeleton|
|Classification:||| Chordata | Reptilia | Thalattosauria | Thalattosauroidea ||
Concavispina is an extinct genus of thalattosaur reptile from the early Late Triassic (Carnian stage) Xiaowa Formation of Guangling, Guizhou, southern China. It contains a single species, Concavispina biseridens. It is known only from the holotype ZMNH M8804, a nearly complete 364 cm long skeleton. Concavispina can be differentiated from other thalattosaurs by possessing two rows of blunt teeth on the anterior part of the maxilla (upper jaw bone) and a V-shaped notch on the dorsal margin of each neural spine in the dorsal (back) vertebrae. Both its generic and specific names refer to these autapomorphies (unique characteristics), as Concavispina means "concave spine" and biseridens means "two rows of teeth". It is thought to be most closely related to Xinpusaurus, as both taxa share three derived characters: a maxilla that is curved upward at its anterior end, a proximal of the humerus or upper arm bone that is wider than the distal end, and the presence of less than five cervical or neck vertebrae.