Leyvachelys

Last updated

Leyvachelys
Temporal range: Late Aptian-Early Albian
~119-113  Ma
O
S
D
C
P
T
J
K
Pg
N
Leyvachelys cipadi - Paja Formation, Colombia.jpg
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Clade: Pantestudines
Clade: Testudinata
Family: Sandownidae
Genus: Leyvachelys
Cadena, 2015
Species:
L. cipadi
Binomial name
Leyvachelys cipadi
Cadena, 2015
Blakey 120Ma - COL.jpg
Paleogeography of Northern South America
120 Ma, by Ron Blakey
Synonyms
  • Glenrosechelys brooksi

Leyvachelys is an extinct genus of turtles in the family Sandownidae from the Early Cretaceous (Late Aptian to Early Albian) of the present-day Altiplano Cundiboyacense, Eastern Ranges, Colombian Andes. The genus is known only from its type species, Leyvachelys cipadi, described in 2015 by Colombian paleontologist Edwin Cadena. Fossils of Leyvachelys have been found in the fossiliferous Paja Formation, 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.

Contents

Fossils of a turtle found in the dinosaur-rich Glen Rose Formation of Texas, 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 cipadi refers to the CIP; the Centro de Investigaciones Paleontológicas, the paleontological research centre outside Villa de Leyva. [1]

Description

The holotype was found on the Loma La Catalina, west of Villa de Leyva, Colombia in 2009. The fossil was discovered in a layer of calcareous claystone 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 ammonites to be Late Barremian to Early Aptian in age. [1]

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, three cervical vertebrae, right humerus and coracoid, both femora, tibiae, and pelvic girdle. The length of the skull is estimated at 15.6 centimetres (6.1 in) and the maximum size of the carapace has been reported as 88 by 108 centimetres (35 by 43 in). The carapace of L. cipadi is the first complete ever found for a sandownid. [1]

Habitat

Plesiosaur and ammonites in the Centro de Investigaciones Paleontologicas (CIP), Villa de Leyva Plesiosaurio.jpg
Plesiosaur and ammonites in the Centro de Investigaciones Paleontológicas (CIP), Villa de Leyva

The Hauterivian 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 and Stenorhynchosaurus , ichthyosaurs as Muiscasaurus and Platypterygius and a plesiosaurs 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 , [2] has been reported. The habitat of Leyvachelys is described as littoral, not open marine as is the case for Desmatochelys. [1] Additionally, many different ammonites and crustaceans are described from the formation. [3] [4] The morphology of the shell of L. cipadi, allows the support of previously hypothesized habitat adaptations for sandownids; in particular, that they inhabited littoral 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. [1]

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), [5] and Colombia (paleocoordinates 3.6° N, 42.2° W) [6] represent the northern and southern paleocoastline of the Early Cretaceous proto-Caribbean Sea. [1]

See also

Related Research Articles

<i>Acanthohoplites</i> Extinct genus of Cretaceous ammonites

Acanthohoplites is an extinct genus of ammonites in the family Parahoplitidae that lived in the Aptian and Early Albian stages of the Early Cretaceous.

<i>Brachauchenius</i> Extinct genus of reptiles

Brachauchenius is an extinct genus of pliosaurid that lived in North America and Morocco during the Late Cretaceous.

<span class="mw-page-title-main">Protostegidae</span> Extinct family of turtles

Protostegidae is a family of extinct marine turtles that lived during the Cretaceous period. The family includes some of the largest sea turtles that ever existed. The largest, Archelon, had a head one metre (39 in) long. Like most sea turtles, they had flattened bodies and flippers for front appendages; protostegids had minimal shells like leatherback turtles of modern times.

<i>Santanachelys</i> Extinct genus of turtles

Santanachelys gaffneyi is an extinct species of sea turtle. It is the only species in the genus Santanachelys, which itself is a member of the extinct family Protostegidae. The species was first described from a 20-centimeter long fossil specimen unearthed in 1998 from the Santana Formation of eastern Brazil. From the rock layer from which it was excavated, it was determined that the specimen was from the Early Cretaceous period. It is therefore one of the oldest known sea turtles. but a new fossil named Desmatochelyspadillai in 2015 is estimated to be as old as 120 million years.

<i>Desmatochelys</i> Extinct genus of turtles

Desmatochelys is an extinct genus of sea turtles belonging to the family Protostegidae. This genus contains two known species, D. lowii and D. padillai. D. lowii was first discovered in 1895, followed by D. padillai in 2015. Having been estimated at over 120 million years old, D. padillai is currently the oldest known species of sea turtle.

<span class="mw-page-title-main">Paja Formation</span> Early Cretaceous geologic formation of central Colombia

The Paja Formation is an Early Cretaceous geologic formation of central Colombia. The formation extends across the northern part of the Altiplano Cundiboyacense, the Western Colombian emerald belt and surrounding areas of the Eastern Ranges of the Colombian Andes. In the subsurface, the formation is found in the Middle Magdalena Valley to the west. The Paja Formation stretches across four departments, from north to south the southernmost Bolívar Department, in Santander, Boyacá and the northern part of Cundinamarca. Well known fossiliferous outcrops of the formation occur near Villa de Leyva, also written as Villa de Leiva, and neighboring Sáchica.

Chubutemys was an extinct genus of meiolaniform turtle. It lived during the Early Cretaceous of Argentina, around the Albian-Aptian border, within the Puesto La Paloma Member of the Cerro Barcino Formation. It is known from most of the skeleton and carapace, and part of the skull.

<span class="mw-page-title-main">Macrobaenidae</span> Extinct family of turtles

Macrobaenidae is an extinct family of turtles, known from the Early Cretaceous to Paleogene of Laurasia. Their relationships to other turtles and whether they form a monophlyletic group are controversial. They are typically interpreted as stem or crown group cryptodires, but some more recent analyses have found them to lie outside crown group Testudines. Macrobaenids can be distinguished from other testudinatans by the presence of a carotid fenestra, cruciform plastron with strap-like epiplastra, and a lack of extragulars.

<i>Padillasaurus</i> Extinct genus of reptiles

Padillasaurus is an extinct genus of titanosauriform sauropod known from the Early Cretaceous Paja Formation in Colombia. It contains a single species, Padillasaurus leivaensis, known only from a single partial axial skeleton. Initially described as a brachiosaurid, it was considered to be the first South American brachiosaurid ever discovered and named. Before its discovery, the only known brachiosaurid material on the continent was very fragmentary and from the Jurassic period. However, a more recent study finds it to be a basal somphospondylan.

<i>Rhinochelys</i> Extinct genus of turtles

Rhinochelys is an extinct genus of sea turtles belonging to the family Protostegidae.

Muiscasaurus is an extinct genus of ophthalmosaurid Ichthyosaur that lived in modern Colombia during the Early Cretaceous. The only known species is the type Muiscasaurus catheti.

<i>Stenorhynchosaurus</i> Extinct genus of reptiles

Stenorhynchosaurus is an extinct genus of pliosaurid plesiosaurs which lived in the Early Cretaceous of South America. The type species and only known is Stenorhynchosaurus munozi. It was a medium-sized pliosaur, reaching an adult body length of 7 m (23 ft).

María Euridice Páramo Fonseca is a Colombian paleontologist and geologist. She has contributed to paleontology in Colombia in the fields of describing various Cretaceous reptiles, most notably the mosasaurs Eonatator and Yaguarasaurus, the ichthyosaur Kyhytysuka, and the plesiosaurs Leivanectes and Stenorhynchosaurus.

Leivanectes is a genus of plesiosaurs of the family Elasmosauridae known from Late Aptian marine deposits in central Colombia. It contains a single species, L. bernadoi, which was described in 2019.

<i>Sachicasaurus</i> Extinct genus of pliosaurid

Sachicasaurus is an extinct genus of brachauchenine pliosaurid known from the Barremian of the Paja Formation, Altiplano Cundiboyacense in the Colombian Eastern Ranges of the Andes. The type species is S. vitae.

<span class="mw-page-title-main">Sandownidae</span> Extinct family of turtles

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, Testudo, Solnhofia, Eurysternum, Plesiochelys, Thalassemys or Protostega, a definition that encompasses the previous concept of the clade while also excluding it from being synonymous with other clades of modern or extinct marine turtles. Sandownidae may be within the larger clade Angolachelonia, defined as inclusive of Angolachelys and Solnhofia, sister to the entirely Late Jurassic marine group Thalassochelydia, although the concepts of the clades may shift with further phylogenetic analysis.

The Bulldog Shale is a formation of Early Cretaceous age that forms part of the Marree Subgroup of the Rolling Downs Group, located in the Eromanga Basin of South Australia, Queensland and New South Wales.

Protolamna is an extinct genus of mackerel shark from the Cretaceous Period. The genus is known from Europe, Asia and North America.

<i>Monquirasaurus</i> Extinct genus of reptiles

Monquirasaurus is an extinct genus of giant short-necked pliosaurs who lived during the Early Cretaceous (Aptian) in what is now Colombia. One species is known, M. boyacensis, described in 2021 from an almost complete fossil skeleton, discovered in 1977 in the town of Villa de Leyva, located in Boyacá. Published descriptions of the holotype specimen estimate that it should reach a total size approaching 8 m (26 ft) in length, making Monquirasaurus a large representative of the pliosaurids.

References

  1. 1 2 3 4 5 6 Cadena, 2015a
  2. Cadena & Parham, 2015b, p.1
  3. Kabakadze & Hoedemaeker, 1997
  4. Bermúdez et al., 2013
  5. SMU 246 at Fossilworks.org
  6. Loma La Catalina at Fossilworks.org

Bibliography