''Itapeuasaurus'' (meaning "Itapeua lizard") is a genus of

rebbachisaurid Rebbachisauridae is a family of sauropod dinosaurs known from fragmentary fossil remains from the Cretaceous of South America, Africa, North America, Europe and possibly Central Asia. Taxonomy In 1990 sauropod specialist Jack McIntosh included t ...

sauropod Sauropoda (), whose members are known as sauropods (; from '' sauro-'' + '' -pod'', 'lizard-footed'), is a clade of saurischian ('lizard-hipped') dinosaurs. Sauropods had very long necks, long tails, small heads (relative to the rest of their bo ...

dinosaur from the Alcântara Formation (Itapecuru Group) of Maranhão in Brazil. The

type Type may refer to: Science and technology Computing * Typing, producing text via a keyboard, typewriter, etc. * Data type, collection of values used for computations. * File type * TYPE (DOS command), a command to display contents of a file. * Ty ...

and only species is ''Itapeuasaurus cajapioensis''. It would have been around to when fully grown and ''Itapeuasaurus'' is the most complete

Cenomanian The Cenomanian is, in the ICS' geological timescale, the oldest or earliest age of the Late Cretaceous Epoch or the lowest stage of the Upper Cretaceous Series. An age is a unit of geochronology; it is a unit of time; the stage is a unit in the s ...

-aged diplodocoid known from South America and it is also the first reported Cenomanian-aged

discovered in South America.

Discovery and naming

In November 2014, fisherman Carlos Wagner Silva discovered a fossilised

humerus The humerus (; ) is a long bone in the arm that runs from the shoulder to the elbow. It connects the scapula and the two bones of the lower arm, the radius and ulna, and consists of three sections. The humeral upper extremity consists of a roun ...

on the beach at Itapeua. In May 2015, paleontologist Manuel Alfredo Medeiros and his students were sent in and they secured several bones, including the holotype, UFMA. 1.10.1960a, which consists of six vertebrae, and a paratype containing around six to seven vertebrae, a humerus and a partial ischium - the largest preserved vertebra reached up to . Because the location where the holotype was found is an intertidal area, excavating the holotype was very hard and could only be excavated around four hours a day during each daily

tidal cycle Tides are the rise and fall of sea levels caused by the combined effects of the gravitational forces exerted by the Moon (and to a much lesser extent, the Sun) and are also caused by the Earth and Moon orbiting one another. Tide tab ...

. In 2019, the species ''Itapeuasaurus cajapioensis'' was named and described.

Phylogeny

Lindoso ''et al.'', (2019) placed ''Itapeuasaurus'' in the

Nigersaurinae Rebbachisaurinae is a subfamily within the family Rebbachisauridae, defined to include ''Rebbachisaurus garasbae'' and exclude '' Limaysaurus tessonei''. It was first proposed as a rank by Jose Bonaparte Jose is the English transliteration of ...

, as the sister taxon to '' Demandasaurus''.

References

Rebbachisaurids Cenomanian life Late Cretaceous dinosaurs of South America Cretaceous Brazil Fossil taxa described in 2019 {{sauropodomorph-stub