Gallardosaurus
Encyclopedia
Gallardosaurus is a genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 of pliosaur
Pliosaur
Pliosauroidea is an extinct clade of marine reptiles. Pliosauroids, also commonly known as pliosaurs, are known from the Jurassic and Cretaceous Periods. The pliosauroids were short-necked plesiosaurs with large heads and massive toothed jaws. These swimming reptiles were not dinosaurs but distant...

id plesiosaur
Plesiosaur
Plesiosauroidea is an extinct clade of carnivorous plesiosaur marine reptiles. Plesiosauroids, are known from the Jurassic and Cretaceous Periods...

 from the Caribbean sea
Caribbean Sea
The Caribbean Sea is a sea of the Atlantic Ocean located in the tropics of the Western hemisphere. It is bounded by Mexico and Central America to the west and southwest, to the north by the Greater Antilles, and to the east by the Lesser Antilles....

way. It contains the single species Gallardosaurus iturraldei. Gallardosaurus was found in middle-late Oxfordian
Oxfordian stage
The Oxfordian is, in the ICS' geologic timescale, the earliest age of the Late Jurassic epoch, or the lowest stage of the Upper Jurassic series. It spans the time between 161.2 ± 4 Ma and 155.7 ± 4 Ma...

-age (Late Jurassic
Late Jurassic
The Late Jurassic is the third epoch of the Jurassic Period, and it spans the geologic time from 161.2 ± 4.0 to 145.5 ± 4.0 million years ago , which is preserved in Upper Jurassic strata. In European lithostratigraphy, the name "Malm" indicates rocks of Late Jurassic age...

) rocks of the Jagua Formation
Jagua Formation
The Jagua Formation is a Late Jurassic geologic formation in Pinar del Rio Province, western Cuba. Plesiosaur, pliosaur, pterosaur, metriorhynchid, and turtle remains are among the fossils that have been recovered from its strata....

 of western Cuba
Cuba
The Republic of Cuba is an island nation in the Caribbean. The nation of Cuba consists of the main island of Cuba, the Isla de la Juventud, and several archipelagos. Havana is the largest city in Cuba and the country's capital. Santiago de Cuba is the second largest city...

. Gallardosaurus is believed to be evolutionarily connected to Peloneustes
Peloneustes
Peloneustes is an extinct genus of sauropterygian reptile belonging to the family Pliosauridae. It is known from the Callovian aged deposits of the Oxford clay formation of England...

, a pliosaurid commonly found in the Oxfordian-aged sediment.

History and etymology

Oxfordian-age reptiles have been found in Cuba since the first half of the 20th century, but most have not received wide recognition because publications were not widely disseminated. In 1996, Dr. Manuel Iturralde-Vinent and Mark Norell initially mentioned specimen MNHNCu
Muséum national d'histoire naturelle
The Muséum national d'Histoire naturelle is the National Museum of Natural History in Paris, France.- History :The museum was formally founded on 10 June 1793, during the French Revolution...

 P3005, a partial skull and mandible with a few cervical
Neck
The neck is the part of the body, on many terrestrial or secondarily aquatic vertebrates, that distinguishes the head from the torso or trunk. The adjective signifying "of the neck" is cervical .-Boner anatomy: The cervical spine:The cervical portion of the human spine comprises seven boney...

 vertebrae, as resembling that of the species Pliosaurus ferox
Pliosaurus
Pliosaurus is a genus of extinct marine reptile. It is included in the family Pliosauridae. Its diet would have included fish, squid and other marine reptiles. This genus has contained several species in the past but it currently consists of the type species P. brachydeirus, P. macromerus and P...

. The specimen had been discovered in 1946 by Cuban farmer Juan Gallardo about 8 kilometres (5 mi) east of Viñales
Viñales
This article is about the town. For the adjacent UNESCO world heritage site, see Viñales Valley. Viñales is a small town and municipality in the north-central Pinar del Rio Province of Cuba....

, Pinar del Río
Pinar del Río Province
Pinar del Río is one of the provinces of Cuba. It is at the western end of the island of Cuba.-Geography:The Pinar del Río province is Cuba's westernmost province and contains one of Cuba's three main mountain ranges, the Cordillera de Guaniguanico, divided into the easterly Sierra del Rosario and...

, northwestern Cuba. However, it was not prepared when Iturralde-Vinent and Norell saw it and a full description was not made. After preparation, Zulma Gasparini and Iturralde-Vinent assigned the specimen to the genus Peloneustes
Peloneustes
Peloneustes is an extinct genus of sauropterygian reptile belonging to the family Pliosauridae. It is known from the Callovian aged deposits of the Oxford clay formation of England...

in 2006, but it was later determined that the specimen was that of a new genus. In 2009, MNHNCu P3005 was described as a separate genus, Gallardosaurus.

The generic name is derived from the specimen MNHNCu P3005's discoverer, Juan Gallardo, who together with Juanito Gallardo is credited with discovering most of the Oxfordian reptiles in Cuba. The species name G. itturraldei is derived from the name of the geotectonist and paleontologist Dr. Manuel Iturralde-Vinent.

MNHNCu P3005 was found in a concretion
Concretion
A concretion is a volume of sedimentary rock in which a mineral cement fills the porosity . Concretions are often ovoid or spherical in shape, although irregular shapes also occur. The word 'concretion' is derived from the Latin con meaning 'together' and crescere meaning 'to grow'...

 in dark shale
Shale
Shale is a fine-grained, clastic sedimentary rock composed of mud that is a mix of flakes of clay minerals and tiny fragments of other minerals, especially quartz and calcite. The ratio of clay to other minerals is variable. Shale is characterized by breaks along thin laminae or parallel layering...

, within the Jagua Vieja Member of the Jagua Formation. It is preserved three-dimensionally with slight deformation. The tip of the snout and the posterior
Anatomical terms of location
Standard anatomical terms of location are designations employed in science that deal with the anatomy of animals to avoid ambiguities that might otherwise arise. They are not language-specific, and thus require no translation...

 ends of the lower jaw are absent. The skull was broad and not tall, with long pointed teeth. The lack of fusion in some of the vertebrae suggests the individual was not fully grown when it died.

Classification

{clade|style=font-size:75% label1= Pliosauridae
Pliosauridae
Pliosauridae is a family of pliosauroid plesiosaurs from the Earliest Jurassic to the early Late Cretaceous of Australia, Europe, North America and South America. It was formally named by Harry G...

 
1=
}}
A cladogram
Cladogram
A cladogram is a diagram used in cladistics which shows ancestral relations between organisms, to represent the evolutionary tree of life. Although traditionally such cladograms were generated largely on the basis of morphological characters, DNA and RNA sequencing data and computational...

 following Gasparini (2009)

Gallardosaurus was a pliosaurid, a member of the family Pliosauridae
Pliosauridae
Pliosauridae is a family of pliosauroid plesiosaurs from the Earliest Jurassic to the early Late Cretaceous of Australia, Europe, North America and South America. It was formally named by Harry G...

, a group of short-necked reptiles that lived during the Mesozoic Era. Other members of the group include Hauffiosaurus
Hauffiosaurus
Hauffiosaurus is an extinct genus of Early Jurassic pliosaurid plesiosaur known from Holzmaden of Germany and from Yorkshire of the United Kingdom. It was first named by Frank Robin O’Keefe in 2001 and the type species is Hauffiosaurus zanoni. In 2011, two additional species were assigned to this...

, Kronosaurus
Kronosaurus
Kronosaurus is an extinct genus of short-necked pliosaur. It was among the largest pliosaurs, and is named after the leader of the Greek Titans, Cronus.-Discovery and species:Kronosaurus lived in the Early Cretaceous Period ....

, Peloneustes
Peloneustes
Peloneustes is an extinct genus of sauropterygian reptile belonging to the family Pliosauridae. It is known from the Callovian aged deposits of the Oxford clay formation of England...

, Liopleurodon
Liopleurodon
Liopleurodon is a genus of large, carnivorous marine reptile belonging to the Pliosauroidea, a clade of short-necked plesiosaurs. Two species of Liopleurodon lived during the Callovian stage of the Middle Jurassic Period , while the third, L. rossicus, lived during the Late Jurassic...

, Brachauchenius
Brachauchenius
Brachauchenius is an extinct genus of pliosaur that lived in America during the Cretaceous.The type species, Brachauchenius lucasi, lived in the Western Inland Sea of North America around 93.5-89.3 million years ago, during the Turonian stage of the Cretaceous...

, and Pliosaurus
Pliosaurus
Pliosaurus is a genus of extinct marine reptile. It is included in the family Pliosauridae. Its diet would have included fish, squid and other marine reptiles. This genus has contained several species in the past but it currently consists of the type species P. brachydeirus, P. macromerus and P...

.

Paleobiology and paleoecology

G. iturraldei would probably have seasonally migrated across the Caribbean Seaway, and would have preyed mostly on nectonic
Nekton
Nekton refers to the aggregate of actively swimming aquatic organisms in a body of water able to move independently of water currents....

 fish that dwelt in the region in which it existed. Also known from the Jagua Vieja Member are ichthyosaur
Ichthyosaur
Ichthyosaurs were giant marine reptiles that resembled fish and dolphins...

s, the marine turtle Caribemys oxfordiensis
Caribemys
Caribemys is an extinct genus of turtle which existed in the Jurassic period. Its fossils have been found in the Jagua Formation in western Cuba. The type species of Caribemys is C. oxfordiensis.-External links:...

, and the plesiosauroid Vinialesaurus caroli
Vinialesaurus
Vinialesaurus is a genus of plesiosaur from the Late Jurassic Jagua Formation of Pinar del Río, Cuba. The type species is Vinialesaurus caroli, first described as Cryptocleidus caroli by De la Torre and Rojas in 1949, and redescribed by Gasparini, Bardet and Iturralde in 2002...

. The water depth was shallow, perhaps 10 to 12 m (32.8 to 39.4 ft) deep, and oysters and algae colonized the sea bottom. Fragmentary remains of plants, pterosaur
Pterosaur
Pterosaurs were flying reptiles of the clade or order Pterosauria. They existed from the late Triassic to the end of the Cretaceous Period . Pterosaurs are the earliest vertebrates known to have evolved powered flight...

s, and dinosaur
Dinosaur
Dinosaurs are a diverse group of animals of the clade and superorder Dinosauria. They were the dominant terrestrial vertebrates for over 160 million years, from the late Triassic period until the end of the Cretaceous , when the Cretaceous–Paleogene extinction event led to the extinction of...

s arrived from nearby coastal areas.
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