Pronunciation: MOH-ro-SOR-us
Meaning: El Morro lizard
Author/s: Rozadilla et al. (2016)
Synonyms: None known
First Discovery: James Ross Island, Antarctica
Discovery Chart Position: #916
Morrosaurus antarcticus
The Antarctic fossil record is a little biased, with Saurischia—the branch that includes theropods and sauropods, playing second fiddle to Ornithischia—the branch that includes thyreophorans and cerapods, in both fossils and genera. With the naming of Morrosaurus in 2016, fourteen years after its initial discovery, the latter outnumbered the former by four to one, which would be a multipliable ratio on fossil-rich continents, and could equate to 8:2, 16:4 or maybe even more. Unfortunately, Antarctica is far from a fossil-rich continent, and as of 2016 their four against one tally is quite literal.
Not to be confused with Morosaurus (with one "r"), which is a synonym of Camarsaurus from the Late Jurassic Morrison of North America, Morrosaurus (with two "r"s) is the fifth dinosaur, behind Cryolophosaurus, Antarctopelta, Glacialisaurus and Trinisaura, to be named from Antarctica. Its holotype amounts to a single leg, and even that is fragmentary. But its not bad, given the shifting glaciers it had to contend with, and it does sport features in common with its yard mate Trinisaura and a bunch of non-hadrosaurian ornithopods from the same period of Patagonia, suggesting Antarctica and Argentina shared a similar fauna during the Late Cretaceous.
Morrosaurus belongs to Elasmaria, a family of ornithopods named for the flat plates found alonside the ribs of its founding members Talenkauen and Macrogryphosaurus, and who all seem to be built for good running. Morrosaurus, however, lacks those plates, so Novas just changed the specifics for inclusion. Gasparinisaura, Notohypsilophodon, Trinisaura and Anabisetia were added to Elasmaria recently, and their remains lack plates too.
Not to be confused with Morosaurus (with one "r"), which is a synonym of Camarsaurus from the Late Jurassic Morrison of North America, Morrosaurus (with two "r"s) is the fifth dinosaur, behind Cryolophosaurus, Antarctopelta, Glacialisaurus and Trinisaura, to be named from Antarctica. Its holotype amounts to a single leg, and even that is fragmentary. But its not bad, given the shifting glaciers it had to contend with, and it does sport features in common with its yard mate Trinisaura and a bunch of non-hadrosaurian ornithopods from the same period of Patagonia, suggesting Antarctica and Argentina shared a similar fauna during the Late Cretaceous.
Morrosaurus belongs to Elasmaria, a family of ornithopods named for the flat plates found alonside the ribs of its founding members Talenkauen and Macrogryphosaurus, and who all seem to be built for good running. Morrosaurus, however, lacks those plates, so Novas just changed the specifics for inclusion. Gasparinisaura, Notohypsilophodon, Trinisaura and Anabisetia were added to Elasmaria recently, and their remains lack plates too.
(El Morro lizard of Antarctica)Etymology
Morrosaurus is derived from "El Morro" (the
peninsula from which it was recovered) and the Greek "sauros" (lizard). The species epithet, antarcticus, refers to Antarctica.
Discovery
The remains of Morrosaurus were discovered in the Cape
Lamb Member of the Snow Hill Formation (initially identified as the López de Bertodano Formation by Del Valle et al.
in 1982), NW of Fortress Hill, El Morro
(The Naze) Peninsula, James Ross Island, Antarctica, by Fernando Novas in 2002.
The holotype (MACN Pv 19777) is a fragmentary right leg.
