Geoemydidae
Encyclopedia
Geoemydidae is the largest and most diverse family
in the order Testudines (turtles) with about 70 species
. It includes the Eurasia
n pond and river turtles and Neotropical wood turtles.
. They usually have webbed toes, and the pelvic girdle articulates with the plastron flexibly. The neck is drawn back vertically. The carapace
has 24 marginal scute
s. The plastron is composed of 12 scutes and has no mesoplastron, the pectoral and abdominal scutes contact the marginal scutes.
Some other features include a single articulation between the fifth and sixth cervical vertebra, the lack of hyomandibular branch of the facial nerve
and an epipterygoid bone in the skull.
, Europe
and North Africa
, the only genus in Central
and South America
is Rhinoclemmys
. The habitats include freshwater ecosystems, coastal marine areas and tropical forests. Most of them are herbivorous
, but there are also some omnivorous
and carnivorous
species. By mating
the males are usually much more active than females. A relatively small number of eggs per clutch
is common, produced several times a year.
Some species have temperature-dependent sex determination system while others possess different sex chromosomes.
About 70% of the extant species have been reported to be in endangered
or vulnerable condition.
as the subfamily Batagurinae
. In the 1980s the subfamily was elevated to the family status and renamed to Geoemydidae according to the ICZN
rules.
The majority of fossil
and molecular data support their close relationship to the family Testudinidae.
The intra-familial taxonomy is not well established yet, due to the large number and diversity of species.
The family is usually divided into two subfamilies and 22 to 27 genera
. The division into subfamilies is currently disputed by some scientists. Several species are known to give viable hybrids, which makes the systematics even more complicated.
Family (biology)
In 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. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
in the order Testudines (turtles) with about 70 species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
. It includes the Eurasia
Eurasia
Eurasia is a continent or supercontinent comprising the traditional continents of Europe and Asia ; covering about 52,990,000 km2 or about 10.6% of the Earth's surface located primarily in the eastern and northern hemispheres...
n pond and river turtles and Neotropical wood turtles.
Characteristics
Geoemydidae are turtles of various sizes (from about 10 to 80 cm in length) with often a high degree of sexual dimorphismSexual dimorphism
Sexual dimorphism is a phenotypic difference between males and females of the same species. Examples of such differences include differences in morphology, ornamentation, and behavior.-Examples:-Ornamentation / coloration:...
. They usually have webbed toes, and the pelvic girdle articulates with the plastron flexibly. The neck is drawn back vertically. The carapace
Carapace
A carapace is a dorsal 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 underside is called the plastron.-Crustaceans:In crustaceans, the...
has 24 marginal scute
Scute
A scute or scutum is a bony external plate or scale, as on the shell of a turtle, the skin of crocodilians, the feet of some birds or the anterior portion of the mesonotum in insects.-Properties:...
s. The plastron is composed of 12 scutes and has no mesoplastron, the pectoral and abdominal scutes contact the marginal scutes.
Some other features include a single articulation between the fifth and sixth cervical vertebra, the lack of hyomandibular branch of the facial nerve
Facial nerve
The facial nerve is the seventh of twelve paired cranial nerves. It emerges from the brainstem between the pons and the medulla, and controls the muscles of facial expression, and functions in the conveyance of taste sensations from the anterior two-thirds of the tongue and oral cavity...
and an epipterygoid bone in the skull.
Ecology
Geoemydidae live in tropics and subtropics of AsiaAsia
Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...
, Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
and North Africa
North Africa
North Africa or Northern Africa is the northernmost region of the African continent, linked by the Sahara to Sub-Saharan Africa. Geopolitically, the United Nations definition of Northern Africa includes eight countries or territories; Algeria, Egypt, Libya, Morocco, South Sudan, Sudan, Tunisia, and...
, the only genus in Central
Central America
Central America is the central geographic region of the Americas. It is the southernmost, isthmian portion of the North American continent, which connects with South America on the southeast. When considered part of the unified continental model, it is considered a subcontinent...
and South America
South America
South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...
is Rhinoclemmys
Rhinoclemmys
Rhinoclemmys is a turtle genus in the family Geoemydidae . They are commonly known as the Neotropical wood turtles and are the only geoemydids known from the Americas...
. The habitats include freshwater ecosystems, coastal marine areas and tropical forests. Most of them are herbivorous
Herbivore
Herbivores are organisms that are anatomically and physiologically adapted to eat plant-based foods. Herbivory is a form of consumption in which an organism principally eats autotrophs such as plants, algae and photosynthesizing bacteria. More generally, organisms that feed on autotrophs in...
, but there are also some omnivorous
Omnivore
Omnivores are species that eat both plants and animals as their primary food source...
and carnivorous
Carnivore
A carnivore meaning 'meat eater' is an organism that derives its energy and nutrient requirements from a diet consisting mainly or exclusively of animal tissue, whether through predation or scavenging...
species. By mating
Mating
In biology, mating is the pairing of opposite-sex or hermaphroditic organisms for copulation. In social animals, it also includes the raising of their offspring. Copulation is the union of the sex organs of two sexually reproducing animals for insemination and subsequent internal fertilization...
the males are usually much more active than females. A relatively small number of eggs per clutch
Clutch (eggs)
A clutch of eggs refers to all the eggs produced by birds or reptiles, often at a single time, particularly those laid in a nest.In birds, destruction of a clutch by predators, , results in double-clutching...
is common, produced several times a year.
Some species have temperature-dependent sex determination system while others possess different sex chromosomes.
About 70% of the extant species have been reported to be in endangered
Endangered species
An endangered species is a population of organisms which is at risk of becoming extinct because it is either few in numbers, or threatened by changing environmental or predation parameters...
or vulnerable condition.
Systematics and evolution
Traditional systematics placed the geoemydids to the family EmydidaeEmydidae
Emydidae, commonly called the pond turtles or marsh turtles, is a family of turtles. Previously, several species of Asian box turtle were classified in the family. However, revised taxonomy has separated them to a different family. Now, Emydidae, with the exception of two species of pond turtle,...
as the subfamily Batagurinae
Batagurinae
Batagurinae is a subfamily of turtles. The following genera are placed here:-Genera:*Genus Batagur *Genus Callagur *Genus Geoclemys...
. In the 1980s the subfamily was elevated to the family status and renamed to Geoemydidae according to the ICZN
International Code of Zoological Nomenclature
The International Code of Zoological Nomenclature is a widely accepted convention in zoology that rules the formal scientific naming of organisms treated as animals...
rules.
The majority of fossil
Fossil
Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...
and molecular data support their close relationship to the family Testudinidae.
The intra-familial taxonomy is not well established yet, due to the large number and diversity of species.
The family is usually divided into two subfamilies and 22 to 27 genera
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
. The division into subfamilies is currently disputed by some scientists. Several species are known to give viable hybrids, which makes the systematics even more complicated.
Subfamilies and genera
The following genera are classified under Geoemydidae.- Subfamily BatagurinaeBatagurinaeBatagurinae is a subfamily of turtles. The following genera are placed here:-Genera:*Genus Batagur *Genus Callagur *Genus Geoclemys...
- Genus BatagurBatagur (genus)Batagur is a genus of turtles. With a recent merger with members from two other genera, this genus now has six described species.-Species:* Batagur affinis* Batagur baska* Batagur borneoensis formerly in Callagur...
(6 species, including part of Kachuga) - Genus Geoclemys (monotypicMonotypicIn biology, a monotypic taxon is a taxonomic group with only one biological type. The term's usage differs slightly between botany and zoology. The term monotypic has a separate use in conservation biology, monotypic habitat, regarding species habitat conversion eliminating biodiversity and...
genus) - Genus Hardella (monotypic genus)
- Genus MoreniaMoreniaMorenia is a genus of turtle in the Geoemydidae family. Members are found in India, Bangladesh and Burma.It contains only the following two species:* Bengal Eyed Terrapin * Indian Eyed Turtle...
(2 species) - Genus PangshuraPangshuraPangshura is a genus of Geoemydidae turtles found in South Asia. Three members were formerly in the genus Kachuga. A fourth member, Pangshura tatrotia, has been described in 2010.-Species:There are four described species:...
(4 species) (formerly in Kachuga)
- Genus Batagur
- Subfamily GeoemydinaeGeoemydinaeGeoemydinae is a subfamily of turtles. The following genera are placed here:* Chinemys * Cuora * Cyclemys * Geoemyda...
- Genus ChinemysChinemysChinemys is a genus of turtle in the family Geoemydidae . It is sometimes included in Mauremys, but they do not seem to be particularly close relatives.Species of the genus Chinemys are:...
, pond turtle (3 species) (sometimes included in Mauremys) - Genus CuoraCuoraAsian box turtles are turtles of the genus Cuora in the family Geoemydidae comprising 10–11 species with about the same number of subspecies. The keeled box turtle is often included in this genus but is also often placed in its own genus...
, Asian box turtle (10 species) (including Cistoclemmys) - Genus CyclemysCyclemysCyclemys, commonly referred to as Asian leaf turtles, is a genus of freshwater turtles from the family Geoemydidae. The genus occurs throughout Southeast and South Asia and currently contains seven species....
(6 species) - Genus GeoemydaGeoemydaGeoemyda is a genus of freshwater turtles in the family Geoemydidae . It contains the following species:* Ryukyu Black-breasted Leaf Turtle, Geoemyda japonica* Black-breasted Hill Turtle, Geoemyda spengleri...
(2 species) - Genus Leucocephalon (formerly in Geoemyda and Heosemys)
- Genus MalayemysMalayemysMalayemys is a genus of turtle in the Geoemydidae family. It was considered monotypic until 2004, but as of 2010 consists of two species. Its found in several countries of Southeast Asia.-Taxonomy:The genus is attributed to Lindholm, 1931....
(2 species) - Genus HeosemysHeosemysHeosemys is a genus of freshwater turtles in the family Geoemydidae . The genus Heosemys was split out of the related genus Geoemyda by McDowell in 1964.-Species:...
(formerly in Geoemyda) - Genus Hieremys (formerly in Geoemyda, often included in Heosemys)
- Genus MauremysMauremysMauremys is a genus of turtle in the family Geoemydidae . Ocadia and Chinemys are included here by some scientists, but not by the majority nor by hobbyists.Species include:...
, pond turtles (including Annamemys, Cathaiemys and Emmenia) - Genus MelanochelysMelanochelysMelanochelys is a genus of turtle in the Geoemydidae family. Members are found in India, Myanmar, Bangladesh, Sri Lanka and Nepal.-Species:Melanochelys contain only the following two species:* Indian black turtle...
(2 species) - Genus Notochelys (monotypic genus)
- Genus OcadiaOcadiaOcadia is a genus of turtle in the family Geoemydidae . It is sometimes included in Mauremys. It contains the following species:* Chinese Stripe-necked Turtle, Ocadia sinensis...
(sometimes included in Mauremys) - Genus Orlitia (monotypic genus)
- Genus Pyxidea, keeled box turtle (often included in Cuora)
- Genus RhinoclemmysRhinoclemmysRhinoclemmys is a turtle genus in the family Geoemydidae . They are commonly known as the Neotropical wood turtles and are the only geoemydids known from the Americas...
, neotropical wood turtles - Genus SacaliaSacaliaSacalia is a genus of turtle in the family Geoemydidae . Species include:* Beal's Eyed Turtle or Beal's Four-eyed Turtle, Sacalia bealei* Four-eyed Turtle, Sacalia quadriocellata...
, "eyed" turtles - Genus SiebenrockiellaSiebenrockiellaSiebenrockiella is a small genus of black marsh turtles. It was formerly monotypic but now has two species with the addition of the Philippine forest turtle...
(2 species, 1 subgenus Panyaenemys, formerly under Heosemys) - Genus Vijayachelys, cane turtle (formerly in Geoemyda and Heosemys)
- Genus Chinemys
External links
- An article about the phylogeny of Geoemydidae http://www2.eve.ucdavis.edu/shafferlab/pubs/SpinksMolPhyloEvo2004.pdf
- Geoemydidae (all species) at The Reptile Database