''Callawayasaurus'' is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

plesiosaur The Plesiosauria or plesiosaurs are an Order (biology), order or clade of extinct Mesozoic marine reptiles, belonging to the Sauropterygia. Plesiosaurs first appeared in the latest Triassic Period (geology), Period, possibly in the Rhaetian st ...

from the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Elasmosauridae Elasmosauridae, often called elasmosaurs or elasmosaurids, is an extinct family of plesiosaurs that lived from the Hauterivian stage of the Early Cretaceous to the Maastrichtian stage of the Late Cretaceous period (c. 130 to 66 mya). The taxo ...

. When the holotype was first described by

Samuel Paul Welles Samuel Paul Welles (November 9, 1909 – August 6, 1997) was an American palaeontologist. Welles was a research associate at the Museum of Palaeontology, University of California, Berkeley. He took part in excavations at the Placerias Quarry in ...

in 1962, it was described as ''Alzadasaurus colombiensis'' before being moved into its current genus by

Kenneth Carpenter Kenneth Carpenter (born 21 September 1949) is an American paleontologist. He is the former director of the USU Eastern Prehistoric Museum and author or co-author of books on dinosaurs and Mesozoic life. His main research interests are armore ...

in 1999.Carpenter, K. 1999. "Revision of North American elasmosaurs from the Cretaceous of the Western Interior". ''Paludicola'' 2(2):148-173.

History

''Callawayasaurus'' is named in honor of the

paleontologist Paleontology, also spelled as palaeontology or palæontology, is the scientific study of the life of the past, mainly but not exclusively through the study of fossils. Paleontologists use fossils as a means to classify organisms, measure geolo ...

Jack M. Callaway, editor of ''Ancient Marine Reptiles'' who, as Carpenter put it, "in his brief career as a vertebrate paleontologist, did much to improve our understanding of marine reptiles." The familiar suffix, ''-saurus'' comes from the Greek ' (), meaning "lizard" or "reptile".

Description

''Callawayasaurus'' was a large plesiosaur, with a skull length of and body length of . The

nare Nare may refer to: People * Daniel Nare, Botswanan football manager * Tadu Teshome Nare (born 2001), Ethiopian runner * Théophile Naré (born 1966), Catholic bishop of Kaya, Burkina Faso Other meanings * Nareh (given name) (or Nare, Nara), Armeni ...

s of ''Callawayasaurus'' are elongated and positioned over the

maxilla In vertebrates, the maxilla (: maxillae ) is the upper fixed (not fixed in Neopterygii) bone of the jaw formed from the fusion of two maxillary bones. In humans, the upper jaw includes the hard palate in the front of the mouth. The two maxil ...

, which has 3-5

teeth A tooth (: teeth) is a hard, calcified structure found in the jaws (or mouths) of many vertebrates and used to break down food. Some animals, particularly carnivores and omnivores, also use teeth to help with capturing or wounding prey, tear ...

. The

neck The neck is the part of the body in many vertebrates that connects the head to the torso. It supports the weight of the head and protects the nerves that transmit sensory and motor information between the brain and the rest of the body. Addition ...

contains 56

vertebrae Each vertebra (: vertebrae) is an irregular bone with a complex structure composed of bone and some hyaline cartilage, that make up the vertebral column or spine, of vertebrates. The proportions of the vertebrae differ according to their spinal ...

which are relatively short compared to other elasmosaurids. ''Callawayasaurus''

fossils A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

have no pectoral bars; in common with other plesiosaurs such as ''

Terminonatator ''Terminonatator'' (meaning "last swimmer") is a genus of elasmosaurid plesiosaur from the Late Cretaceous of Saskatchewan, Canada. It is known from a skull and partial skeleton from a young adult, found in the Campanian-age Bearpaw Formation ...

''. They also lack postaxial accessory facets. Another nearly complete

skeleton A skeleton is the structural frame that supports the body of most animals. There are several types of skeletons, including the exoskeleton, which is a rigid outer shell that holds up an organism's shape; the endoskeleton, a rigid internal fra ...

was found to be slightly more robust than the

holotype A holotype (Latin: ''holotypus'') is a single physical example (or illustration) of an organism used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of s ...

specimen Specimen may refer to: Science and technology * Sample (material), a limited quantity of something which is intended to be similar to and represent a larger amount * Biological specimen or biospecimen, an organic specimen held by a biorepository f ...

. This subtle change may indicate

sexual dimorphism Sexual dimorphism is the condition where sexes of the same species exhibit different Morphology (biology), morphological characteristics, including characteristics not directly involved in reproduction. The condition occurs in most dioecy, di ...

Paleoenvironment

The first ''Callawayasaurus'' remains were found in the

Paja Formation The Paja Formation (, K1p, Kip, Kimp, b3b6p) is an Early Cretaceous formation (geology), geologic formation of central Colombia. The formation extends across the northern part of the Altiplano Cundiboyacense, the Colombian emeralds#Western belt, W ...

near Leiva, Boyaca

Colombia Colombia, officially the Republic of Colombia, is a country primarily located in South America with Insular region of Colombia, insular regions in North America. The Colombian mainland is bordered by the Caribbean Sea to the north, Venezuel ...

. The specific name for 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. * ...

, "''columbiensis''", means "from Colombia". ''Callawayasaurus'' are known from the

Aptian The Aptian is an age (geology), age in the geologic timescale or a stage (stratigraphy), stage in the stratigraphic column. It is a subdivision of the Early Cretaceous, Early or Lower Cretaceous epoch (geology), Epoch or series (stratigraphy), S ...

faunal stage In chronostratigraphy, a stage is a succession of rock strata laid down in a single age on the geologic timescale, which usually represents millions of years of deposition. A given stage of rock and the corresponding age of time will by conven ...

of the early

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ...

period Period may refer to: Common uses * Period (punctuation) * Era, a length or span of time *Menstruation, commonly referred to as a "period" Arts, entertainment, and media * Period (music), a concept in musical composition * Periodic sentence (o ...

, which extended from 125 to 112 million years ago.

References

External links

Information on plesiosaurs, including images of a ''Callawayasaurus'' skull
{{Taxonbar, from=Q2634949 Elasmosauridae Early Cretaceous plesiosaurs Early Cretaceous reptiles of South America Plesiosaurs of South America Cretaceous Colombia Fossils of Colombia Altiplano Cundiboyacense Paja Formation Fossil taxa described in 1999 Taxa named by Kenneth Carpenter Sauropterygian genera

History

Description

Paleoenvironment

See also

References

External links