Molecular Biology and Genetics
Statistics of barcoding coverage
|Specimen Records:||86||Public Records:||19|
|Specimens with Sequences:||64||Public Species:||4|
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Caiman venezuelensis is an extinct species of caiman that lived in South America during the Pleistocene. The holotype of C. venezuelensis — OR-1677, a partial left premaxilla bone — was discovered in the locality of El Breal of Orocual, in the Mesa Formation, in the state of Monagas, Venezuela, the country of which derives their species name.
The premaxilla preserved measures 24.6 mm long, with an estimated total length of 28-30 millimeters. It has a strong premaxillary sutural surface, a hole developed in the fourth tooth of the jaw bone, and short spaces between the alveoli, indicating that despite its size, their characteristics were different from the current young alligatorids and thus corresponds to subadult or adult individual. Then C. venezuelensis could one of the smallest known species of alligatorids, even smaller than the dwarf caimans of the genus Paleosuchus. It is also distinguished from other alligatorids have long narrow premaxilla, about twice as long as wide.
Despite the abundance of fossil sites of the Pliocene and Pleistocene in South America, the remains of crocodilians of these periods are scarce and fragmentary and generally little studied. C. venezuelensis is one of the few findings confirmed of a distinct species of this period and may help clarify the history of this group after the Miocene.
- Daniel Costa Fortier y Ascanio Daniel Rincón (2012). Pleistocene crocodylians from Venezuela, and the description of a new species of Caiman. Quaternary International. In press, DOI:dx.doi.org/10.1016/j.quaint.2012.03.018.
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Caiman is a genus of reptile in the Alligatoridae family. They are found in Central and South America, and differ from the alligator by the absence of a bony septum between the nostrils, and the ventral armour is composed of overlapping bony scutes, each of which is formed of two parts united by a suture. Caimans tend to be more agile and crocodile-like in their movements, and have longer, sharper teeth than alligators. Although the Caiman has not been studied in-depth, scientists have learned that their mating cycles (previously thought to be spontaneous or year-round) are linked to the rainfall cycles and the river levels, which increases chances of survival for their offspring.
In Caiman the dura covering the medullary region of the brain is proportionally thicker than the dura covering the forebrain, although this might not impact the ratio in volume between the regions.
The genus contains three extant species, two extant subspecies and two extinct species:
- Yacare Caiman, Caiman yacare
- Spectacled Caiman, Caiman crocodilus
- Caiman lutescens (fossil)
- Caiman sorontans (fossil) - Not reported in the literature, probably a 'nomen nudum'
- Broad-snouted Caiman, Caiman latirostris
- ^ "Allometric Comparison," Larsson (2001). Page 26.
- Larsson, H.C.E. 2001. Endocranial anatomy of Carcharodontosaurus saharicus (Theropoda: Allosauroidea) and its implications for theropod brain evolution. pp. 19–33. In: Mesozioc Vertebrate Life. Ed.s Tanke, D. H., Carpenter, K., Skrepnick, M. W. Indiana University Press.
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