The narrow-bridged musk turtle (''Claudius angustatus'') is a

species In biology, a species is the basic unit of Taxonomy (biology), classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of ...

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 ...

in the

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

Kinosternidae The Kinosternidae are a family of mostly small turtles that includes the mud turtles and musk turtles. The family contains 25 species within four genera, but taxonomic reclassification is an ongoing process, so many sources vary on the exact nu ...

. The species is found in

Central America Central America ( es, América Central or ) is a subregion of the Americas. Its boundaries are defined as bordering the United States to the north, Colombia to the south, the Caribbean Sea to the east, and the Pacific Ocean to the west. ...

and

Mexico Mexico ( Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guate ...

Geographic range

''C. angustatus'' is found in

, Guatemala, and

Belize Belize (; bzj, Bileez) is a Caribbean and Central American country on the northeastern coast of Central America. It is bordered by Mexico to the north, the Caribbean Sea to the east, and Guatemala to the west and south. It also shares a wa ...

Taxonomy

As of 2010, ''C. angustatus'' is the only recognized

extant species Neontology is a part of biology that, in contrast to paleontology, deals with living (or, more generally, ''recent'') organisms. It is the study of extant taxa (singular: extant taxon): taxa (such as species, genera and families) with members sti ...

in the

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial n ...

''Claudius''.

Description

The narrow-bridged musk turtle is typically brown in color. The

scute A scute or scutum (Latin: ''scutum''; plural: ''scuta'' "shield") is a bony external plate or scale overlaid with horn, as on the shell of a turtle, the skin of crocodilians, and the feet of birds. The term is also used to describe the anterior po ...

s of the

carapace A carapace is a 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 tortoises, the und ...

have lines and graining, imparting an almost wood-like appearance. It often has bright-yellow markings on the edges of the carapace. As it ages,

algae Algae ( , ; : alga ) are any of a large and diverse group of photosynthetic, eukaryotic organisms. The name is an informal term for a polyphyletic grouping that includes species from multiple distinct clades. Included organisms range from ...

often heavily cover the shell, masking the patterning and coloration. The head is large and bulbous for its size, with a sharp beak and a long neck. The jaw joint anatomy of the narrow-bridged musk turtle is unique among modern

Cryptodira The Cryptodira ('' el, hidden neck'') are a suborder of Testudines that includes most living tortoises and turtles. Cryptodira differ from Pleurodira (side-necked turtles) in that they lower their necks and pull the heads straight back into t ...

. In most cryptodires the jaw joint is formed by a biconcave facet. In the narrow-bridged musk turtle, the jaw joint of is formed by a broad hemispherical condyle, more akin to

Pleurodira The Pleurodira are one of the two living suborders of turtles, the other being the Cryptodira. The division between these two suborders represents a very deep evolutionary divide between two very different types of turtles. The physical differe ...

. The carapace is

dome A dome () is an architectural element similar to the hollow upper half of a sphere. There is significant overlap with the term cupola, which may also refer to a dome or a structure on top of a dome. The precise definition of a dome has been a ...

d, with three distinct ridges down the length. Though classified in the subfamily

Staurotypinae The Staurotypinae are a subfamily of the family Kinosternidae of aquatic turtles, which contains the genera '' Claudius'' and ''Staurotypus''. ''Staurotypus'' exhibits XX/XY sex determination, in contrast to the temperature-dependent sex deter ...

with the "giant" musk turtles, the narrow-bridged musk turtle generally only grows to a straight carapace length of about 6.5 in (16.5 cm). The narrow-bridged musk turtle exhibits genetic sex determination, in contrast to most turtles; although the mechanism is not known for certain, it is suspected to be

XX/XY ''XX/XY'' is a 2002 American romantic drama film written and directed by Austin Chick and starring Mark Ruffalo, Kathleen Robertson, and Maya Stange. The title refers to the different chromosome pairings present in men and women. XX/XY premier ...

like that of its relative ''

Staurotypus ''Staurotypus'' is a genus of aquatic turtles, commonly known as giant musk turtles, Mexican musk turtles, or three-keeled musk turtles, in the family Kinosternidae. The genus contains two recognized species, which are endemic to Mexico and Cent ...

''.

Behavior, habitat, and diet

Like all musk turtles, the narrow-bridged musk turtle is almost entirely aquatic, and prefers

habitat In ecology, the term habitat summarises the array of resources, physical and biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species habitat can be seen as the physical ...

s such as slow-moving creeks, or shallow ponds that are heavily vegetated. It spends much of its time walking along the bottom,

foraging Foraging is searching for wild food resources. It affects an animal's fitness because it plays an important role in an animal's ability to survive and reproduce. Foraging theory is a branch of behavioral ecology that studies the foraging behavi ...

for aquatic

insect Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body (head, thorax and abdomen), three pairs ...

s and other

invertebrate Invertebrates are a paraphyletic group of animals that neither possess nor develop a vertebral column (commonly known as a ''backbone'' or ''spine''), derived from the notochord. This is a grouping including all animals apart from the chordate ...

s, and

carrion Carrion () is the decaying flesh of dead animals, including human flesh. Overview Carrion is an important food source for large carnivores and omnivores in most ecosystems. Examples of carrion-eaters (or scavengers) include crows, vultures ...

. It has glands under the rear of the

shell Shell may refer to: Architecture and design * Shell (structure), a thin structure ** Concrete shell, a thin shell of concrete, usually with no interior columns or exterior buttresses ** Thin-shell structure Science Biology * Seashell, a hard o ...

from which it can release a foul-smelling

musk Musk ( Persian: مشک, ''Mushk'') is a class of aromatic substances commonly used as base notes in perfumery. They include glandular secretions from animals such as the musk deer, numerous plants emitting similar fragrances, and artificial s ...

, hence its common name.

References

External links