Family Pedetidae

The Family Pedetidae is comprised of large rodents known as Springhares. The family consists of four genera, three of which are now extinct. The only extant genera, Pedetes, persist with two known species: Pedetes surdaster, the East African Spring-hare and Pedetes capensis, the Springhare or Springhaas. Both species are found in the Southern region of Africa. Pedetes capensis can be found from the southern tip of the African continent to the southern region of the Democratic Republic of Congo, while Pedetes surdaster is found primarily throughout Tanzania and southern Kenya. Fossil evidence shows the family origins began in the Miocene while the current extant genera have origins in the Pliocene. Their preferred habitat is grasslands with sandy soil suitable for burrowing. They often are seen at night foraging in groups of varying sizes, feeding on grasses, forbs, and other vegetation. Their tendency to forage on agriculture products has made them a nuisance, but they are also a valuable source of meat. Although they have been endangered in past years, protected regions have helped to secure their numbers throughout Africa.

The primary source of movement in the Pedetidae is hopping on their hind legs called ricochetal locomotion. Although they primarily hop, Springhares will also use their front legs for walking. The short front legs, long hind legs, and a long bushy tail make the Springhare similar to the kangaroo. The fur is thin, brownish red, with the tip of the tail being black. They have short heads, muscular necks, and large skulls that house long ears and big eyes. Interestingly, the tragus of their long ears can close the ear canal while burrowing. The front legs are built for burrowing with five long claws, while the hind legs are suited for rapid movement having four wide claws.

Work Cited
Jackson, A. 2000. “Pedetes capensis” (On-line), Animal Diversity Web. Accessed February 06, 2015 at https://animaldiversity.org/accounts/Pedetes_capensis/
Butynski, T.M. & De Jong, Y. 2008. Pedetes surdaster. The IUCN Red List of Threatened Species. Version 2014.3. . Downloaded on 06 February 2015.
Author: Edward Peebles

Family Geomyidae

The family Geomyidae has been established as being closely related to the family Heteromyidae, with both of these families being included in the superfamily Geomyidaea. Fossil record evidence has placed the separation of Geomyidae and Heteromyidae into two distinct families in the early Oligocene. The large number of recognizable taxa within this family is likely due to their small population size and tendency to specialize. This family is made up of 6 different genera, and 40 different species. The family Geomyidae is commonly referred to as the “pocket gophers.” This name comes from the distinguishing fur-lined cheek pouches of this group. These pouches are used for food transport, and they extend from the side of the mouth into the shoulders. Notable species include Geomys bursarius, the plains pocket gopher.

Geoymids are found only in North and Central America. They are a fossorial group, meaning they live most of their lives underground. Their bodies are highly modified to fit this lifestyle, including short but powerful legs and claws on the forefeet. The skull is robust and angular in overall appearance, which is a trait that helps to distinguish the group from the heteromyids. These animals can move both forwards and backwards with equal ease, and it is thought that their short tails can provide important sensory information that aids with this movement. Geomyids have small eyes and ears, and an enlarged lacrimal gland that is believed to provide fluids to wash out dirt. The lips of geomyids are also adapted to burrowing, as they can be closed behind the incisors in order to allow the incisors to be used to dig without filling the mouth with dirt. The teeth of this group are ever-growing.

Geomyids are active burrowers, creating different tunnels for different purposes. Their burrow systems include long, shallow tunnels that are used for foraging, and deeper tunnels used for nesting and food storage, as well as for latrines. These burrows are important to the surrounding ecosystem, as they are used by a variety of other species. Geomyids are generally solitary animals, and they come together solely to reproduce. They eat primarily tubers and roots, and consume an incredible amount of plants.

Work Cited
Myers, P. 2001. “Geomyidae” (On-line), Animal Diversity Web. Accessed December 14, 2014 at https://animaldiversity.org/accounts/Geomyidae/
“Pocket Gophers (Family Geomyidae).” Pocket Gophers (Family Geomyidae). Web. 15 Dec. 2014. <https://kufs.ku.edu/libres/mammals_of_kansas/geomys-burs.html>.

Author: Lauren Naylor

Family Heteromyidae

The family Heteromyidae has been established as being closely related to the family Geomyidae, with both of these families being included in the superfamily Geomyidaea. Fossil record evidence has placed the separation of Geomyidae and Heteromyidae into two distinct families in the early Oligocene. Heteromyids are thought to have originated in the Oligocene in Western North America. The lineages later diversified within the Neogene. Members of Heteromyidae are primarily deciduous thorn-scrub and arid-adapted rodents of medium to small size. This family is made up of 60 species that are placed into 3 subfamilies and 6 genera, which are divided as follows: Perognathinae, containing Chaetodipus and Perognathus , Heteromyinae containing Heteromy and Liomys, and finally Dipodomyinae containing Dipodomys and Microdipodops, Notable species within this family include kangaroo rats and pocket mice.

Heteromyids range from western North American, down through Mexico and Central American and into northwestern South America. Many species live in deserts and dry grasslands, although members of Heteromys and Liomys can be found in both wet and dry tropical forests. All members of this family have a large, fur lined pouch in their cheek. It opens next to the mouth and extends back along the shoulders. This pouch is used for food storage. Heteromyids feed on seeds and plant parts, and sometimes animal matter. They can store this food in their cheek pouch as a way of transporting it back to their burrow. Most heteromyids burrow, and can form complex tunnel systems that are made up of multiple chambers and openings. The overall skeletal structure of the skull of a heteromyid can vary between species, but as a whole they have thin and papery skulls with underdeveloped ridges and crests. This feature helps to distinguish them from their relatives the geomyids, who all have robust skulls. Heteromyids are sciuromorphus and sciurognathus, and their cheek teeth are hyposodont. In all but the kangaroo rats, however, their teeth are not evergrowing. In most other aspects, such as pelage texture and color, the specific characteristics vary between species.

 

Work Cited
Alexander, Lois F., and Brett R. Riddle. “Phylogenetics Of The New World Rodent Family Heteromyidae.” Journal of Mammalogy 86.2 (2005): 366-79. Web. 21 Nov. 2014. <https://faculty.unlv.edu/riddle/pdf/Alexander_Riddle_2005.pdf>.
Myers, P. 2001. “Heteromyidae” (Online), Animal Diversity Web. Accessed November 21, 2014 at https://animaldiversity.ummz.umich.edu/accounts/Heteromyidae/

Author: Lauren Naylor

Family Castoridae

The family Castoridae includes all modern beavers and their fossil relatives. There is only one genus, Castor, and two species within this genus. These two species are Castor fiber, the European beaver and Castor canadensis, the North American Beaver. The geologic record of this family extends back to the Oligocene, with Castoroides and Palaeocastor being well known extinct members. Members of Castoridae occupy the northern temperate zone, where they serve an important ecological role. They often fell trees due to their feeding on bark and leaves, and their preferences for certain tree types have an impact on the tree species composition in the surrounding area. The building of dams, digging of canals and borrows also modifies the streams and lakes that they occupy. The resulting flooding creates habitats for various different species of wildlife.

Castorids live in small family groups, and mark specific territories with scent mounds. When frightened, they loudly slap the water with their tails as a warning to their family and as a method of startling any potential predator. They are semiaquatic, and use a pelage of long guard hairs and dense underfur for insulation. This coat has made them a target for fur trappers in the past. To aid with their locomotion in water they have a flattened tail and webbed hind feet. Their eyes are protected by nictating membrane, and their nostrils and ears can be closed as well. An interesting characteristic of castorids is that their epiglottis lies above the soft palate in the narial passage. This allows air to flow through without actually entering the mouth cavity. The back of the tongue can rise up to fit against the palate to block the passage of water from the mouth. This characteristic allows castorids to open their mouth underwater to gnaw or carry branches.

 

Work Cited
Myers, P. 2000. “Castoridae” (On-line), Animal Diversity Web. Accessed October 20, 2014 at https://animaldiversity.ummz.umich.edu/accounts/Castoridae/

Author: Lauren Naylor

Family Cuniculidae

The two species are Cuniculus paca, the lowland paca and Cuniculus taczanowskii, the mountain paca. The pacas’ fossil records began in the Oligocene. They are found in Central and South America ranging from east central Mexico to Paraguay. Overall, their biogeographic region consists of the southern portion of the new world, the neotropics. Their preferred habitat is near rivers and streams in tropical forests. Near these water sources, the pacas are found at sea level to about 300 m elevation. This family consists of plant-eating rodents who compete with other species for food sources due to overlapping diets and habitats. Also, the pacas’ economic importance for humans is both positive and negative because they are considered a tender and mild-flavored food source as well as a crop pest in some areas.

Cuniculids are known to be terrestrial, nocturnal, and solitary mammals that prefer to be alongside bodies of water for the construction of burrows in banks, slopes, or between rocks and tree roots. The water sources provide an efficient escape from predators; however, they usually do not dive or forage in the water. Although they are solitary rodents, pacas communicate by use of vocalizations, foot thumping, and tooth grinding. An interesting characteristic of cuniculids is their morphology. They have chunky bodies with short, stout legs; however, their hind limbs are longer than their forelimbs. They have large heads with large eyes. They are nearly tailless. The cuniculids have coarse pelage without under fur. Their skulls are also unmistakable because they are broad and massive with short nasals and long frontals. The pacas’ zygomatic arches are inflated to form a hollow, resonating chamber that is used to amplify sound.

 

Work Cited
Myers, P. 2000. “Cuniculidae” (On-line), Animal Diversity Web. Accessed November 22, 2014 at https://animaldiversity.ummz.umich.edu/accounts/Cuniculidae/#behavior

Author: Stacie Garcia

Family Bathyergidae

The family Bathyergidae contains African mole rats and is within the suborder Hystricomorpha of the order Rodentia. Evidence shows that members of this family belong to the Old World Hystricognathi lineage and are closely related to Petromuridae, Thyronomyidae, and Hystricidae. The divergence of the Old World and New World lineages occurred during the Eocene in Africa. Bathyergids originate in sub-Saharan Africa and are small to medium sized. Bathyergidae consists of 5 genera and 16 species. The genera are Georychus, Heterocephalus, Heliophobius, and Bathyergus. These five genera are further separated into two subfamilies. The first subfamily, Bathyerginae, includes the genus Bathyergus and its two species. This subfamily is characterized by large front claws and a groove in their upper incisors. The second subfamily, Heterocephalinae, includes the genera Georychus, Heliophobius, Cryptomys, and Heterocephalus. This subfamily lacks the large claws and groove in their upper incisors. Species within this family include the naked mole-rat and the silvery mole-rat.

All members of the family live fossorial lifestyles and have physical characteristics to accommodate such a living. These characteristics include short legs, a tapered body, small ears and eyes, and large incisors. In order to burrow, bathyergids utilize their powerful incisors to loosen dirt and then move said dirt away from their path with their short arms. This is true for all members of the family apart from the genus Bathyergus, which uses its arms to burrow. Due to the presence of small eyes, bathyergids do not use sight frequently, if at all, when underground. The sense of touch, however, is vital to the family. When underground, bathyergids feel for their surroundings by using their short tails and long hairs made specifically for such purpose. Members also have hypsodont dentition, which reflects their herbivorous diet. Compared to other rodents, bathyergids have a much longer lifespan, which is often between 12 and 26 years. The genera Heterocephalus and Cryptomys are unique based on their social systems, which can include one mating female along with several males and non-mating female helpers.

 

Work Cited
Kingdon et al. (2013). Mammals of Africa, Volumes 1-6. Retrieved from https://www.books.google.com/
Myers, P. 2000. “Bathyergidae blesmoles and mole rats.” (Online). Animal Diversity Web. Accessed April 15, 2015 at https://animaldiversity.org/accounts/Bathyergidae/

Author: Anna Cole

Family Chinchillidae

Chinchillidae is a family of medium to large-sized chinchillas and viscachas in the order Rodentia, the suborder Hystricomorpha, and the Infraorder Hystricognathi. Little research has been conducted regarding the family’s phylogenetic history. However, recent studies have shown that the family is a monophyletic clade that is related to Dinomyidae, another small mammalian family from South America. The family Chinchillidae includes three extinct genera and three extant genera: Chinchilla, consisting of the species Chinchilla chinchilla and Chinchilla lanigera, Lagidium with the species Laguidium peruanum, Lagidium viscacia, Lagidium wolffsohni, and Lagidium ahuacaense, and Lagostomus with the species Lagostomus maximus. The family Chinchillidae first appeared in South America during the Oligocene. Members of the family commonly live in areas with rocky terrain, open areas, and shrub lands. Animals habituating in higher elevations protect themselves by burrowing, but are not known for their speed or adept digging capabilities. Animals habituating in the plains, however, live in subterranean colonies and are able to navigate efficiently enough to evade predators.

Members of Chinchillidae originated in Southern South America, specifically in the Andes mountains. Adaptations to fit this rough and rocky terrain include fleshy foot pads, called pallipes, strong hind legs, and long bushy tails. Chinchillids are herbivorous and have cheek teeth that continue to grow throughout the individual’s life. The chinchillid jaw is also hystricognathous based on the absence of an infraorbital plate and the partial passage of muscles through the infraorbital foramen. Additional adaptations include short front legs and long back legs. This reflects the occassional locomotion of bipedal jumping exhibited by chinchillids. The number of digits varies between chinchillas and viscachas, with the former have four and the latter having three. Chinchillas are a popular commodity in the pet trade and clothing industry due to their cute appearance and soft fur. Because of this, the wild population is decreasing dramatically, and is considered to be critically endangered.

 

Work Cited
Myers, P. 2000. “Chinchillidae chinchillas and viscachas” (Online). Animal Diversity Web. Accessed February 24, 2015 at https://animaldiversity.org/accounts/Chinchillidae/
Spotorno, A. et al. (2004). “Molecular divergence and phylogenetic relationships of chinchillids.” Journal of Mammalogy 85.3 (2004). Web. 24 February 2015.
Vaughn, T. et al. (2013). Mammalogy. Pg. 227-228. Retrieved from: https://www.books.google.com

Author: Anna Cole

Family Ctenomyidae

The family Ctenomyidae, known as tuco-tucos, includes one genus, Ctenomys with 65 species; all are found in central and southern South America up to 4,000 m in elevation. The fossil record show that the family extends to the early Pliocene and that they are closely related to the family Octodontidae. Ctenomys are fossorial species with small ears and eyes and powerful bodies. They inhabit mostly areas with sandy and loamy soil with a few species living in dry grasslands. They dig using their forefeet which are equipped with extremely long and strong claws to loosen the packed earth to build complex, branched burrow systems. Ctenomys urinate on the compacted soil in order to soften the ground for them to dig with their claws, as well as their incisors. These burrow systems are built with different chambers that are used for nesting and storing food, such as roots, stems and grasses that they store to feed on.

In a few of the Ctenomys species there is a complex social system and the burrows are used by many individuals, but in most other species the burrows in the colonies are used by single individuals or mothers with young. The species use vocalization to communicate various signals, such as establishing territories, in mating rituals or as a fear response. When some species are threaten and confronted by an intruder they will attack; other species when threatened will back into their burrows and use their tail as a sensing organ. The complex burrows systems that Ctenomys build are used by other mammals, lizards, toads, invertebrates and sometimes birds as shelter. Although tucos-tucos can damage crops and the root systems of the fruit trees, and the burrows create problems for livestock, they also aerate and fertilize the soil helping with the maintenance of soil fertility for other plants benefiting herbivores, as well growth of crops.

 

Work Cited
Myers, P. 2000. “Ctenomyidae” (Online), Animal Diversity Web. Accessed January 23, 2015 at https://animaldiversity.org/accounts/Ctenomyidae/

Author: Rebeca Mendez

Family Thryonomyidae

The family Thryonomyidae, also called cane rats, has one genus, Thryonomys, which includes two species: T. gregorianus (the Lesser cane rat) and T. swimderianus (the Greater cane rat). The family dates to the Eocene with fossils distributed in Asia, Europe and Africa. The family can now be found south of the Sahara in Africa. Thryonomyids are mostly found in wet or swampy areas that have abundant grass, and they sometimes extend into agricultural areas. T. gregorianus uses tall grass for shelter and they sometimes dig shallow burrows or use rock crevices, termite mounds and abandoned aardvark or porcupine holes as shelter. On other occasions this species was observed inhabiting edges along swamps. T. swimderiamus are the more fully aquatic of the two species and they occur near marshes and river banks occasionally expanding into habitats near farmlands.

Thryonomys are large (4 to 6 kg) and have stocky bodies and limbs that are short and powerful with thick, strong claws that are adapted for digging. Thryonomys males initiate courtship by wagging their tails and treading their hind legs. Males duel by pushing each other nose to nose to establish dominance within their social group hierarchy. These nocturnal herbivores make well defined paths that go from feeding areas to water by pounding down dense grass. This family is sometimes found in small groups, but are usually solitary. Thryonomys hold an important significance as wild animals for humans in that in some areas they are hunted for their high protein meat. Due to their value as a source of protein humans have started to domesticate them, which helps to relieve the pressure placed on the wild populations.

 

Work Cited
Myers, P. 2000. “Thryonomyidae” (Online), Animal Diversity Web. Accessed January 23, 2015 at https://animaldiversity.org/accounts/Thryonomyidae/
Antonanza, R.L., Sen, S. and Mein, P. 2004. Systematics and phylogeny of the cane rats (Rodentia: Thryonomyidae). Zoological Journal of the Linnean Society. 142: 423–444

Author: Rebeca Mendez

Family Zapodidae

The family Zapodidae is met with some controversy, as there are varied opinions about the status as a distinct family or as a subfamily of the Old World Family Dipodidae. They were described as being separated from the Old World by Coues in 1875. We treat it as a distinct family for this website. The group currently recognizes three genera and five species. This family is collectively known as jumping mice, and they are mostly restricted to the middle and northern parts of North America. Their habitat generally consists of moist meadows and the edge of woodlands, although some species prefer deep forests near streams.

Only one non-American species, Eozapus setchuanus, is known. It is native to China, and is the only representative of the genus Eozapus. The other two genera, Zapus and Napaeozapus, are native to North America. The main difference between the two American genera is the absence of a minute upper premolar in Napaeozapus. As a family, the members closely resemble each other, especially in size and color. They are slightly larger than the common house mouse, and have long limbs. Their coloration is yellowish brown on top, with a white underside and a broad line of yellowish orange separating the two sides. Napaeozapus also has a characteristic white tip on the tail.

Members of Zapodidae serve an important ecological role through seed dispersal. Napaeozapus insignis, or the western jumping mouse, is thought to benefit trees of economic importance through their dispersal of mycorrhizal fungi. They also are of some importance as a prey species for a variety of animals, including gray wolves and bobcats. Many species of Zapodidae are primarily nocturnal, although they are known to forage during daytime hours as well. Members of this group burrow and build underground nests, where they then spend winters in hibernation. They are active for only a short time each year. The normal mode of locomotion is a quadrupedal walk, although a quadrupedal hop is also used. This hop can be as long as 1.8 m, although the average is around 0.9 m, and can be as high as 0.6 m. Jumping mice are omnivorous generalists, with primary food sources including fruits, seeds, fungi and insects. All members of Zapodidae are listed as being of Least Concern on the IUCN RedList.

 

Work Cited
Allen, J.A. “The North-American Jumping Mice.” The American Naturalist 34.399 (1900): 199-202. Jstor. Web. 1 Mar. 2015. .
Harrington, E. 2004. “Napaeozapus insignis” (On-line), Animal Diversity Web. Accessed March 02, 2015 at https://animaldiversity.org/accounts/Napaeozapus_insignis/
Mockler, R. 2002. “Zapus princeps” (On-line), Animal Diversity Web. Accessed March 02, 2015 at https://animaldiversity.org/accounts/Zapus_princeps/

Author: Lauren Naylor

Family Muridae

The family Muridae consists of rats, mice, and their relatives from the Old World, and currently includes 5 subfamilies. These subfamilies further diversified into 150 genera and 730 species from multiple radiations that occurred in Asia during the Miocene, making it the largest mammal group. Genetic evidence indicates that these radiations resulted in the five lineages of murids. The first subfamily is Deomyinae, an African and Asian group that includes the spiny mice. The subfamily Gerbillinae, gerbils and relatives, is found in arid regions of Africa through the Middle East and into Asia. These small mice share many arid-adaptations with other mammals like kangaroo rats and jerboas. The subfamily Leimacomyinae contains only a single species, the grooved toothed forest mouse, from tropical Africa. The Otomyinae contains the whistling rats and vlei rats restricted to sub-Saharan Africa. Finally, the subfamily Murinae contains 561 species of which are generically called Old World rats and mice. Though current evidence supports these subfamilies, relations within Muridae continue to be evaluated. Members of Muridae are native to Australia, Europe, Africa and Asia, including parts of Micronesia, but are found worldwide, except for Antarctica, as commensals. Murids ,therefore, occupy a great diversity of habitats such as tropical forests, wetlands, and deserts and can be semi-aquatic, fossorial, or terrestrial. Diets also vary, as species can be herbivorous, omnivorous, or carnivorous.

Characteristics of murid skulls include an enlarged infraorbital foramen with a keyhole shape, a broad zygomatic plate, the lack of a postorbital process, and a sciurognathus lower jaw. In a sciurognathous jaw, the angular process and incisors begin at the same area. Each side of the jaw also includes one incisor each on the top and bottom rows, and does not include premolars. Most murids have three ever-growing molars. Shared physical characteristics include four claws on each front foot and five claws on the back feet. Other characteristics vary due to the different habitats populated by murids. Certain species of Muridae have historically carried diseases that devastate human and animal populations alike. Other species, however, maintain both insect populations and the quality of forests.

 

Work Cited
Myers, P. 2001. “Muridae Old World mice and rats, gerbils, whistling rats, and relatives” (Online). Animal Diversity Web. Accessed April 15, 2015 at https://animaldiversity.org/accounts/Muridae/
Michaux, J. et al. “Evolutionary History of the Most Speciose Mammals: Molecular Phylogeny of Muroid Rodents.” Mol Biol Evol 18.11 (2001): 2017-2031. Web. April 15, 2015. https://mbe.oxfordjournals.org/citmgr?gca=molbiolevol%3B18%2F11%2F2017
Vaughan, T.A., Ryan, J.M. and Czaplewski, N.J. 2015.Mammalogy, 6th edition. Jones and Bartlett Learning, Burlington, MA.

Author: xxx

Family Platacanthomyidae

The family Platacanthomyidae is comprised of small rodents. This family includes two species with two genera, Platacanthomys and Typhlomys. The two species are Platacanthomys lasiurus, Malabar Spiny Dormice, and Typhlomys cinereus, Pygmy Dormice. This family is found in southern India, southern China, and northern Vietnam. Overall, they have a discontinuous Old World distribution. Their preferred habitat is moist, rocky, tropical, and subtropical forests at an elevation of 600 to 2100 meters. Since Platacanthomyids are herbivores, they are primary consumers in their ecosystems. Their positive economic importance for humans is unknown at this time, but unfortunately this family does have a negative economic impact for humans. In India, the species Platacanthomys lasiurus is abundant and known as the pepper rat since it destroys pepper crops.

This family is known to be arboreal, scansorial, nocturnal, and motile. Commonly located near a stream, the Platacanthomyids occupy burrows, tree cavities, and clefts between rocks. The genus Platacanthomys uses their large, tufted tails to balance when hopping between branches. Overall, the platacanthomyids are mouse like in their appearance with a body length ranging from 70 to 212 mm. Their feet are slim and small with five medium long digits. They have naked feet that have six pads each. Skulls have a small and delicate dentary bone. Lastly, the species Typhlomys cinereus is critically endangered and listed on the IUCN Red List due to habitat destruction.

 

Work Cited
Poor, Allison. 2005. ” Platacanthomyidae ” (Online), Animal Diversity Web. Accessed January 26, 2015 at https://animaldiversity.org/accounts/Platacanthomyidae/ Updated September1, 2005

Author: Stacie Garcia

Family Spalacidae

The family Spalacidae is part of the superfamily Muroidea, which contains five other rodent families including Muridae and Cricetidae. Ancestors of Spalacidae first appeared in Asia during the Oligocene, with the family later appearing in the Miocene. During this time, the spalacids spread out underground, where they developed into the three modern subfamilies. These subfamilies then further radiated to their current locations. Spalacidae includes 3 subfamilies and 6 genera, which together include 36 species. The subfamilies are Myospalacinae including the genera Myospalax and Eospalax, Rhizomyinae including the genera Cannomys and Rhizomys, and Spalacinae including the genera Spalax. Species within the Spalacidae family include such animals as the zokors. Previously, Tachyoryctinae was a fourth subfamily, but recent molecular research has shown that the genus Tachyoryctes is in fact a sister group of Rhizomys, and has thus been incorporated into the subfamily Rhizomyinae.

Members of Spalacidae are found all throughout the Old World. Specifically, spalacids are found from Western to Eastern Europe, East Africa, the Middle East, and from China to Sumatra in Asia. Spalacids are either fossorial or semi-fossorial, and burrow in areas with damp soil, typically in grasslands or savannah. Members of Spalacidae are small to medium-sized rodents and have robust bodies, small eyes and limbs, and enlarged incisors. Though some species are naked, most members have a think coat of fur. The large front teeth serve as the primary mechanism for burrowing in all members except those belonging to Myospalacinae, which utilize limbs to dig underground. In addition to large incisors, spalacids also have hypsodont dentition, which indicates an herbivorous diet. Sexual dimorphism is not seen in most species. However, some species such as Tachyoryctes splendens exhibit larger males than females. In addition to large incisors, certain Spalacids have developed other adaptations to a subterranean lifestyle. Members of the genus Spalax have tumor suppressors that counteract cell death, which can occur when the body receives little oxygen. These tumor suppressants have been found to prevent and halt cancer development in organisms. Research is currently being conducted to find possible drug applications of these suppressants.

 

Work Cited
Honeycutt, R. et al. “The phylogenetic position of the zokors (Myospalacinae) and comments on the families of muroids (Rodentia).” Molecular Phylogenetics and Evolution 31.3 (2004): 972-978.
Poor, A. 2005. “Spalacidae blind mole rats, African mole rats, zokors, and bamboo rats” (Online). Animal Diversity Web. Accessed March 29, 2015 at https://animaldiversity.org/accounts/Spalacidae/.
Lin et al. “Transcriptome sequencing and phylogenetic resolution within Spalacidae (Rodentia).” BMC Genomics 15.32 (2014).
Manov et al. “Pronounced cancer resistance in a subterranean rodent, the blind mole-rat, Spalax: in vivo and in vitro evidence.” BMC Biology 11.91 (2013).

Author: Anna Cole

Family Aplodontiidae

The Aplondontiidae family consists of one species Aplodontia rufa, the mountain beaver. Mountain beavers have no close relation to the North American beaver. This family extends back to the Miocene, with the genus Myagaulidae being an extinct member. The family can be found in the Nearctic Region, from central California to southern British Columbia. They are found from sea level to the tree line in high mountain peaks within the deciduous and coniferous forest, primarily in moist habitats. Aplodontia are large rodents that weigh approximately 1.5 kg with short tails and coarse dull, fur. This family vocalizes with booming and whistling sounds; when fighting they squeal and grind their teeth to make noise.

They live in complex burrows with openings that are covered with vegetation or sticks. The burrows have interconnecting tunnels that lead to chambers used for denning, feeding, and storage of food, fecal pellets and refuse. They spend around 75 % of their time inside the burrows only moving around to areas of close proximity to their burrows (Zielinski et. al 2010). Although they are not a social species they often build their nests in concentrated colonies with overlapping territories; there they defend their burrows from other individuals. From the close proximity of their burrows, these herbivores feed on forbs, grasses and ferns; while feeding the mountain beaver re-ingests their soft fecal pellets by catching the excreted pellets into their mouths, a process known as coprophagy.

 

Work Cited
Myers, P. 2000. “Aplondontiidae” (Online), Animal Diversity Web. Accessed November 23, 2014 at https://animaldiversity.ummz.umich.edu/accounts/Aplodontiidae/
Zielinski, W.J., J.E. Hunter, R. Hamlin, K.M. Slauson, and M. J. Mazurek. 2010. Habitat Characteristics at Den Sites of the Point Arena Mountain Beaver (Aplodontia rufa nigra). Northwest Science 84:119-130.

Author: Rebecca Mendez