| Central Texas pocket gopher | |
|---|---|
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Order: | Rodentia |
| Family: | Geomyidae |
| Genus: | Geomys |
| Species: | G. texensis |
| Binomial name | |
| Geomys texensis Merriam, 1895 | |
The central Texas pocket gopher or Llano pocket gopher (Geomys texensis) is a species of rodent in the family Geomyidae. It is endemic to central Texas in the United States. [1]
The central Texas pocket gopher is very similar in appearance to its close relatives, the plains pocket gopher and Knox Jones's pocket gopher, and the three species can be difficult to distinguish visually. Males average 18 cm (7.1 in) in length, and females 15 cm (5.9 in); both sexes have a tail about 6 or 7 cm (2.4 or 2.8 in) long. The fur is brownish over most of the body, with a paler, yellowish collar about the throat, and white underparts and feet. The winter coat is darker than the summer one, with the underparts sometimes pale grey in color. [2]
Geomys texensis can primarily be found in central Texas. Northern specimens reside in stretches along McCulloch, San Saba, and Lampasas counties, and extend to Zavala, Frio, and Medina counties in the south. [3] The three subspecies of Geomys texensis (llanensis, texensis, and bakeri) are located in several clades over these ranges, and they are typically characterized as being northern or southern-dwelling.
Northern specimens G. t. texensis and G. t.llanesis are parapatric in their distribution. [3] That is, their respective ranges do not overlap, however, they are immediately adjacent to each other. The third subspecies, G. t. bakeri, is geographically isolated from the other two subspecies, and can primarily be found in the southern counties of Medina, Uvalde, and Zavala. [2] The significant geographic segregation between the three subspecies has recently been highlighted, as genetic implications associated with habitat range are currently being investigated. Primarily, genetic differences between the northern-dwelling G. t. texensis and G. t.llanesis, and the southern-dwelling G. t. bakeri are being examined. [3]
The lack of cranial morphological differentiation between G. texensis and its sibling species have posed problems for scientists attempting to affirm the characteristics unambiguously associated with G. texensis. Conservation of morphological characters, that scientists postulate arose from adaptations to a fossorial lifestyle, is one reason G. texensis and its pocket gopher siblings look alike. [4]
Genetic isolation is rarely complemented by morphological evolution. This phenomenon leads to the need for a more comprehensive understanding of the genetic makeup of G. texensis and its siblings.
Due to recent major advancements in the field of genetics, DNA sequencing is now a useful method scientists use to characterize and understand organisms. The need for expanded sampling of G. texensis has been recognized as an important goal in differentiating G. texensis from other members of its taxa. This is because there is limited morphological divergence among taxa related to G. texensis. [5] Extensive population sampling is the likely first step scientists will take in order to collect genetic data sets on G. texensis.
The development of advanced molecular techniques is what led to the elevation of G. texensis to species status. [6] Mitochondrial cytochrome-b is often used as a template for DNA sequencing, and it has successfully been used to construct phylogenetic relationships between G. texensis and its subspecies. Cytochrome-b has previously been used to reconstruct phylogenetic relationships between rodents, so it is currently a preferred method in regards to genetic analysis.
Chromosomal examination of G. texensis and its proximate taxa is another method researchers have utilized in order to better understand what distinguishes G. texensis from other pocket gophers. [7] Distinctions between gophers in this particular model are based on differing diploid number and chromosomal morphology. In particular, the geographic distribution of the northern G. texensis subspecies have 2n=70–72, but with altering morphology. Additionally, the southern-dwelling specimens have 2n=70, 71, 72, or 74. [7]
As its name implies, the species is found only in central Texas, where it inhabits areas with loamy soils suitable for digging. They are solitary animals, occupying tunnel systems that are typically at least 2 m (6 ft 7 in) apart. The burrows contain multiple chambers, including food caches and latrines in addition to resting chambers, and vertical corkscrew tunnels to deter predators. They give birth to a litter once each year. [2]
One species of Ischnoceran chewing louse, Geomydoecus heaneyi, is only known to live in the fur of central Texas pocket gophers. [2]
Three subspecies have been identified: [2]
Pocket gophers, commonly referred to simply as gophers, are burrowing rodents of the family Geomyidae. The roughly 41 species are all endemic to North and Central America. They are commonly known for their extensive tunneling activities and their ability to destroy farms and gardens.
Botta's pocket gopher is a pocket gopher native to western North America. It is also known in some areas as valley pocket gopher, particularly in California. Both the specific and common names of this species honor Paul-Émile Botta, a naturalist and archaeologist who collected mammals in California in 1827 and 1828.
The yellow-faced pocket gopher is a species of pocket gopher that is native to shortgrass prairies in the south-western United States and northern Mexico. It is the species that lives north of the Southern Coahuila Filter-Barrier (SCFB). Among the different species, the yellow-faced pocket gopher has a small to medium-sized skull. The fossil of this genus was recorded from the pre-Pleistocene Benson Beds of Arizona.
The southeastern pocket gopher is a species of pocket gopher that is native to the southeastern United States. It occurs in Alabama, Georgia, and Florida, where it is the only pocket gopher.
The genus Geomys contains 12 species of pocket gophers often collectively referred to as the eastern pocket gophers. Like all pocket gophers, members of this genus are fossorial herbivores.
The desert pocket gopher is a species of rodent in the family Geomyidae. It is found in the state of Chihuahua in Mexico and in Texas and New Mexico in the United States.
The plains pocket gopher is one of 35 species of pocket gophers, so named in reference to their externally located, fur-lined cheek pouches. They are burrowing animals, found in grasslands and agricultural land across the Great Plains of North America, from Manitoba to Texas. Pocket gophers are the most highly fossorial rodents found in North America.
The Texas pocket gopher is a species of rodent in the family Geomyidae. It is found in Tamaulipas in Mexico and in Texas in the United States.
Buller's pocket gopher is a species of gopher that is endemic to Mexico.
The camas pocket gopher, also known as the camas rat or Willamette Valley gopher, is a rodent, the largest member in the genus Thomomys, of the family Geomyidae. First described in 1829, it is endemic to the Willamette Valley of northwestern Oregon in the United States. The herbivorous gopher forages for vegetable and plant matter, which it collects in large, fur-lined, external cheek pouches. Surplus food is hoarded in an extensive system of tunnels. The dull-brown-to-lead-gray coat changes color and texture over the year. The mammal's characteristically large, protuberant incisors are well adapted for use in tunnel construction, particularly in the hard clay soils of the Willamette Valley. The gophers make chattering sounds with their teeth; males and females make purring sounds when they are together, and the young make twittering sounds. Born toothless, blind and hairless, the young grow rapidly before being weaned at about six weeks of age.
The mountain pocket gopher is a species of rodent in the family Geomyidae. It is endemic to California and Nevada. The Sierra Nevada are part of its range.
Baird's pocket gopher or the Louisiana pocket gopher is a species of pocket gopher that is native to the southern United States. In total, there are three almost identical species of eastern pocket gopher; Geomys attwateri, G. bursarius, and G. breviceps. G. breviceps is larger in size, G. attwateri is medium-sized and G. bursarius is a bit smaller. Other than by size variation they are not identifiable by external features. Baird's pocket gophers are small rodents with most of their weight on the top half of their bodies.
The Haile Quarry or Haile sites are an Early Miocene and Pleistocene assemblage of vertebrate fossils located in the Haile quarries, Alachua County, northern Florida. The assemblage was discovered during phosphate mining, which began in the late 1940s. Haile sites are found in the Alachua Formation. Two sites within the Ocala Limestone yielded Upper Eocene Valvatida and mollusks.
Knox Jones's pocket gopher is a species of pocket gopher found in Texas and New Mexico. This species is named for Dr. J. Knox Jones Jr. (1929–1992), a prolific mammalogist at Texas Tech University.
The Oriental Basin pocket gopher is a species of pocket gopher which is endemic to Mexico. It was first described in 1895 by Clinton Hart Merriam. It was considered to be a subspecies of Merriam's pocket gopher in the late 20th and early 21st century but has been reinstated as its own species. The IUCN Red List has evaluated it to be of least concern.
The Perote pocket gopher, or Cofre de Perote pocket gopher, is a species of pocket gopher in the family Geomyidae.
Geomys jugossicularis, also known as Hall's pocket gopher and Colorado pocket gopher, is a species of pocket gopher native to the western United States. Little is known of its behavior or ecology aside from typical behaviors of the other pocket gophers.
Geomys lutescens, also known as the Sand Hills pocket gopher, is a species of pocket gopher native to the western United States. It is a fossorial rodent that inhabits the Mississippi basin. The common name is derived from the type locality of Sand Hills.
Geomys streckeri, also known as Strecker's pocket gopher, is a species of pocket gopher found in Texas. It was formerly considered a subspecies of the Texas pocket gopher. Chromosomal analyses have proven this species to be distinct. Analysis of its mitochondrial cytochrome b points to this species being a sister clade to Geomys personatus, Geomys attwateri, and Geomys tropicalis. Other evidence, using a Bayesian analysis of ribosomal RNA and certain proteins, points to it being embedded within the G. personatus clade and being a sister species to G. attwateri.
