''Leyvachelys'' is an extinct

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

turtle Turtles are an order of reptiles known as Testudines, characterized by a special shell developed mainly from their ribs. Modern turtles are divided into two major groups, the Pleurodira (side necked turtles) and Cryptodira (hidden necked tu ...

s in the family

Sandownidae Sandownidae is a family of extinct marine turtles from the Cretaceous and Paleogene distributed around the Atlantic Ocean and adjacent areas. The family is defined as all taxa closer to the type genus '' Sandownia'' than to ''Pelomedusa'', '' Tes ...

from the

Early Cretaceous The Early Cretaceous ( geochronological name) or the Lower Cretaceous (chronostratigraphic name), is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 145 Ma to 100.5 Ma. Geology Pro ...

( Late Aptian to Early Albian) of the present-day Altiplano Cundiboyacense, Eastern Ranges,

Colombia Colombia (, ; ), officially the Republic of Colombia, is a country in South America with insular regions in North America—near Nicaragua's Caribbean coast—as well as in the Pacific Ocean. The Colombian mainland is bordered by the Car ...

Andes The Andes, Andes Mountains or Andean Mountains (; ) are the longest continental mountain range in the world, forming a continuous highland along the western edge of South America. The range is long, wide (widest between 18°S – 20°S ...

. The genus is known only from its

type species In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specimen ...

, ''Leyvachelys cipadi'', described in

2015 File:2015 Events Collage new.png, From top left, clockwise: Civil service in remembrance of November 2015 Paris attacks; Germanwings Flight 9525 was purposely crashed into the French Alps; the rubble of residences in Kathmandu following the Apri ...

by Colombian paleontologist Edwin Cadena. Fossils of ''Leyvachelys'' have been found in the fossiliferous

Paja Formation Paja may refer to: * Paja, Iran, a village in Sari County * Paja (given name), a Serbian masculine name * Paja (surname) * Paja Formation, geologic formation in Colombia * Paja Brava :''Paja Brava is also used in Spanish speaking countries to ...

, close to Villa de Leyva, Boyacá, after which the genus is named. The holotype specimen is the oldest and most complete sandownid turtle found to date. Fossils of a turtle found in the dinosaur-rich Glen Rose Formation of

Texas Texas (, ; Spanish language, Spanish: ''Texas'', ''Tejas'') is a state in the South Central United States, South Central region of the United States. At 268,596 square miles (695,662 km2), and with more than 29.1 million residents in 2 ...

, informally named ''Glenrosechelys brooksi'', have been assigned to the same genus and type species.

Etymology

The genus name is derived from Villa de Leyva and ''chelys'' means "turtle" in Greek. The species

epithet An epithet (, ), also byname, is a descriptive term (word or phrase) known for accompanying or occurring in place of a name and having entered common usage. It has various shades of meaning when applied to seemingly real or fictitious people, di ...

''cipadi'' refers to the CIP; the Centro de Investigaciones Paleontológicas, the paleontological research centre outside Villa de Leyva.

Description

The

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of several ...

was found on the Loma La Catalina, west of Villa de Leyva,

in 2009. The fossil was discovered in a layer of calcareous

claystone Mudrocks are a class of fine-grained siliciclastic sedimentary rocks. The varying types of mudrocks include siltstone, claystone, mudstone, slate, and shale. Most of the particles of which the stone is composed are less than and are too sm ...

with abundant occurrences of ferruginous-calcareous nodules and concretions. The section belongs to the middle segment of the Paja Formation called "Arcillolitas abigarradas Member" and has been dated on the basis of

ammonite Ammonoids are a group of extinct marine mollusc animals in the subclass Ammonoidea of the class Cephalopoda. These molluscs, commonly referred to as ammonites, are more closely related to living coleoids (i.e., octopuses, squid and cuttlefish) ...

s to be Late Barremian to Early Aptian in age.Cadena, 2015a The turtle is the earliest recorded sandownid turtle in the world and the first of this family discovered in South America. The fossil find consists of a fairly complete skull, a well-preserved lower jaw and postcrania with an almost complete

carapace A carapace is a Dorsum (biology), dorsal (upper) section of the exoskeleton or shell in a number of animal groups, including arthropods, such as crustaceans and arachnids, as well as vertebrates, such as turtles and tortoises. In turtles and tor ...

, three cervical vertebrae, right humerus and coracoid, both femora,

tibia The tibia (; ), also known as the shinbone or shankbone, is the larger, stronger, and anterior (frontal) of the two bones in the leg below the knee in vertebrates (the other being the fibula, behind and to the outside of the tibia); it connects ...

e, and pelvic girdle. The length of the skull is estimated at and the maximum size of the carapace has been reported as . The carapace of ''L. cipadi'' is the first complete ever found for a sandownid.

Habitat

The

Hauterivian The Hauterivian is, in the geologic timescale, an age in the Early Cretaceous Epoch or a stage in the Lower Cretaceous Series. It spans the time between 132.9 ± 2 Ma and 129.4 ± 1.5 Ma (million years ago). The Hauterivian is preceded by the Va ...

to Late Aptian Paja Formation is one of the richest fossiliferous stratigraphic units of Colombia, where other marine reptiles are found too. Pliosaurs as ''

Kronosaurus ''Kronosaurus'' ( ; meaning "lizard of Kronos") is a potentially dubious genus of extinct short-necked pliosaur. With an estimated length of , it was among the largest pliosaurs, and is named after the leader of the Greek Titans, Kronos. It l ...

'' and '' Stenorhynchosaurus'',

ichthyosaur Ichthyosaurs (Ancient Greek for "fish lizard" – and ) are large extinct marine reptiles. Ichthyosaurs belong to the order known as Ichthyosauria or Ichthyopterygia ('fish flippers' – a designation introduced by Sir Richard Owen in 1842, altho ...

s as '' Muiscasaurus'' and ''

Platypterygius ''Platypterygius'' is a historically paraphyletic genus of platypterygiine ichthyosaur from the Cretaceous period. It was historically used as a wastebasket taxon, and most species within ''Platypterygius'' likely are undiagnostic at the genus or ...

'' and a

plesiosaur The Plesiosauria (; Greek: πλησίος, ''plesios'', meaning "near to" and ''sauros'', meaning "lizard") or plesiosaurs are an order or clade of extinct Mesozoic marine reptiles, belonging to the Sauropterygia. Plesiosaurs first appeared ...

s known as '' Callawayasaurus'' represent the known marine reptile fauna assemblage of the formation. From the Paja Formation in the same year as ''Leyvachelys'', the oldest sea turtle known in the world, ''

Desmatochelys padillai ''Desmatochelys'' (from Greek δεσμός ''desmos'' 'link' + χέλῡς ''khelus'' ‘tortoise’) is an extinct genus of sea turtles belonging to the family Protostegidae. This genus contains two known species, ''D. lowii'' and ''D. padillai' ...

'',Cadena & Parham, 2015b, p.1 has been reported. The habitat of ''Leyvachelys'' is described as

littoral The littoral zone or nearshore is the part of a sea, lake, or river that is close to the shore. In coastal ecology, the littoral zone includes the intertidal zone extending from the high water mark (which is rarely inundated), to coastal areas ...

, not open marine as is the case for ''Desmatochelys''. Additionally, many different

s and

crustacea Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean gro ...

ns are described from the formation.Kabakadze & Hoedemaeker, 1997Bermúdez et al., 2013 The morphology of the shell of ''L. cipadi'', allows the support of previously hypothesized habitat adaptations for sandownids; in particular, that they inhabited

to near-shore shallow marine environments, and that their general body-plan was not designed for leading an open marine lifestyle. They nevertheless potentially shared niches with open marine turtles, as evidenced by the occurrence of protostegids as ''Desmatochelys'', from the same stratigraphical horizons. The abundant occurrence of molluscs, principally ammonites, some of them preserved associated with the carapace of ''L. cipadi'', suppose a potential source of food for its durophagous diet adaptation which could have also included arthropods, as for example crabs. Fossil turtle fragments, initially and informally described as ''Glenrosechelys brooksi'', found in the contemporaneous to slightly younger Glen Rose Formation of Texas have been assigned to the same genus ''Leyvachelys''. Both occurrences in Texas (paleocoordinates 30.0° N, 55.5° W),SMU 246
at

Fossilworks Fossilworks is a portal which provides query, download, and analysis tools to facilitate access to the Paleobiology Database The Paleobiology Database is an online resource for information on the distribution and classification of fossil animals ...

.org and Colombia (paleocoordinates 3.6° N, 42.2° W)Loma La Catalina
at

.org represent the northern and southern paleocoastline of the Early Cretaceous proto-Caribbean Sea.

Etymology

Description

Habitat

See also