Callawayasaurus is a
genusIn biology, a genus is a taxonomic unit used in the classification of living and fossil organisms. The term comes from Latin genus "descent, family, type, gender" , cognate with – genos, "race, stock, kin" ..In addition, genus is a taxonomic rank in the hierarchy In biology, a genus (plural:...
of
plesiosaurA plesiosaur was a type of carnivorous aquatic reptile. After their discovery, plesiosaurs were somewhat fancifully said to have resembled "a snake threaded through the shell of a turtle", although they had no shell...
from the
familyIn biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus...
ElasmosauridaeElasmosauridae was the family of plesiosaurs. They had the longest necks of the plesiosaurs and survived from the Early Jurassic to the end of the Cretaceous. They had a diet of fish and shelless cephalopods.-Size:...
. When the first
Callawayasaurus fossilFossils are the preserved remains or traces of animals, plants, and other organisms from the remote past. The totality of fossils, both discovered and undiscovered, and their placement in fossiliferous rock formations and sedimentary layers is known as the fossil record...
was first discovered by
Samuel Paul WellesSamuel Paul Welles was an American palaeontologist, who was Research Associate at the Museum of Palaeontology, University of California, Berkeley. He took part in excavations at the 'Placerias Quarry' in 1930 and the Shonisaurus discoveries of 1954 and later, in what is now the Berlin-Ichthyosaur...
in 1962, he described it as
Alzadasaurus colombiensis before it was moved into its current genus by
Kenneth CarpenterKenneth Carpenter is a Paleontologist at the Denver Museum of Natural History and author or co-author of a number of books on dinosaurs and Mesozoic life...
in 1999.
Callawayasaurus (
Callaway) is named in honor of the paleontologist, 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".
Callawayasaurus is a
genusIn biology, a genus is a taxonomic unit used in the classification of living and fossil organisms. The term comes from Latin genus "descent, family, type, gender" , cognate with – genos, "race, stock, kin" ..In addition, genus is a taxonomic rank in the hierarchy In biology, a genus (plural:...
of
plesiosaurA plesiosaur was a type of carnivorous aquatic reptile. After their discovery, plesiosaurs were somewhat fancifully said to have resembled "a snake threaded through the shell of a turtle", although they had no shell...
from the
familyIn biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus...
ElasmosauridaeElasmosauridae was the family of plesiosaurs. They had the longest necks of the plesiosaurs and survived from the Early Jurassic to the end of the Cretaceous. They had a diet of fish and shelless cephalopods.-Size:...
. When the first
Callawayasaurus fossilFossils are the preserved remains or traces of animals, plants, and other organisms from the remote past. The totality of fossils, both discovered and undiscovered, and their placement in fossiliferous rock formations and sedimentary layers is known as the fossil record...
was first discovered by
Samuel Paul WellesSamuel Paul Welles was an American palaeontologist, who was Research Associate at the Museum of Palaeontology, University of California, Berkeley. He took part in excavations at the 'Placerias Quarry' in 1930 and the Shonisaurus discoveries of 1954 and later, in what is now the Berlin-Ichthyosaur...
in 1962, he described it as
Alzadasaurus colombiensis before it was moved into its current genus by
Kenneth CarpenterKenneth Carpenter is a Paleontologist at the Denver Museum of Natural History and author or co-author of a number of books on dinosaurs and Mesozoic life...
in 1999.
Etymology
Callawayasaurus (
Callaway) is named in honor of the paleontologist, 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
sauros (σαυρος), meaning "lizard" or "reptile."
Description
The first
skullThe skull is a bony structure found in the head of many animals. The skull supports the structures of the face and protects the head against injury....
of
Callawayasaurus to be found was 35 cm long, while the animal as a whole grew up to 8 m long. The nares of
Callawayasaurus are elongated and positioned over the
maxillaThe maxilla is a fusion of two bones along the palatal fissure that form the upper jaw. This is similar to the mandible , which is also a fusion of two halves at the mental symphysis. Sometimes , the maxilla is sometimes called "upper maxilla", with the mandible being the "lower maxilla"...
, which has 3-5 teeth.
The
neckThe neck is the part of the body on many terrestrial or secondarily aquatic vertebrates that distinguishes the head from the torso or trunk. The Latin term signifying "of the neck" is cervical.-Bony anatomy: The cervical spine:...
contains 56 vertebrae which are relatively short compared to other elasmosaurids.
Callawayasaurus fossils have no pectoral bars; in common with other plesiosaurs such as
TerminonatatorTerminonatator 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 near Notukeu Creek in Ponteix...
. They also lack postaxial accessory
facetFacets are flat faces on geometric shapes. The organization of naturally occurring facets was key to early developments in crystallography, since they reflect the underlying symmetry of the crystal structure...
s.
Another nearly complete
skeletonIn biology, a skeleton is a rigid framework that provides protection and structure in many types of animal, particularly those of the phylum Chordata and of the superphylum Ecdysozoa. Exoskeletons are external, as is typical of many invertebrates; they enclose the soft tissues and organs of the...
was found to be slightly more robust than the
holotypeA holotype is one of several possible biological types. A type is what fixes a name to a taxon. A holotype is a single physical example of an organism, known to have been used when the species was formally described...
specimenIn biology, a specimen is an individual animal, part of an animal, plant, part of a plant, or microorganism used as a representative to study the properties of the whole population of that species or subspecies...
. This subtle change may indicate
sexual dimorphismSexual dimorphism is the systematic difference in form between individuals of different sex in the same species. Examples include colour , size, and the presence or absence of parts of the body used in courtship displays or fights, such as ornamental feathers, horns, antlers or tusks.-Examples:In...
.
Distribution
The fist
Callawayasaurus remains were found in the Paja Formation near
LeivaVilla de Leyva is a colonial town and municipality, in the Boyacá department, part of the subregion of the Ricaurte Province. The town is located some 40 km west of Tunja and has a population of about 4,000 people...
,
BoyacaBoyacá is one of the 32 Departments of Colombia, and the remnant of one of the original nine states of the "United States of Colombia".Boyacá is centrally located within Colombia, almost entirely within the mountains of the Eastern Cordillera to the border with Venezuela, although the western end...
ColombiaColombia , officially the Republic of Colombia , is a constitutional republic in northwestern South America. Colombia is bordered to the east by Venezuela and Brazil; to the south by Ecuador and Peru; to the north by the Caribbean Sea; to the northwest by Panama; and to the west by the Pacific Ocean...
.
The species name for the type, "
columbiensis", means "from Columbia."
Callawayasaurus are known from the
AptianThe Aptian is an age in the geologic timescale or a stage in the stratigraphic column. It is a subdivision of the Early or Lower Cretaceous epoch or series and encompasses the time from 125.0 ± 1.0 Ma to 112.0 ± 1.0 Ma , approximately...
faunal stageIn chronostratigraphy, a stage is a succession of rock strata laid down in an 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 convention have the same name, and the same boundaries.Rock...
of the early
CretaceousThe Cretaceous , Latin language for "chalky", usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago . In the geologic timescale, the Cretaceous follows on the Jurassic period and is followed by the Paleogene period of the...
period, which extended from 125 to 112 million years ago.
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