Texas Tech University

Glossary

acrocentric. Designation for a chromosome with the centromere at or near one of its ends.

adult. Generally, a sexually mature and breeding individual in a population.

adult pelage. The type of hair covering characteristic of adults of the species.

aerial. Pertaining to mammals that have the capacity for sustained flight. Bats are the only aerial mammal.

aestivate. To pass the summer or dry season in a dormant condition. Same as estivate.

agonistic behavior. Fighting or combative behavior.

allopatric. Of populations or species occupying mutually exclusive, but usually adjacent, geographical areas.

allozyme. Variants of an enzyme coded by different alleles at the same locus.

alluvial. Pertaining to the soil, sand, and gravel deposited by a running watercourse where it issues from a canyon or gorge onto an open plain.

altricial. Pertaining to young born in a very underdeveloped condition, requiring extended development and parental care. Opposite of precocial.

alveolus. A socket in the jaw bone for the root or roots of a tooth.

anal gland. A gland located near the anus.

angular process. The posteroventral projection of the mandible (lower jaw), located ventrally to the coronoid process and mandibular condyle.

ankle. The joint in the hind limb between the tibia and fibula of the lower leg and the tarsal bones of the foot.

annual molt. A once yearly shedding and replacing of hair in mammals.

annulation. A circular or ring-like formation, as of the dermal scales on the tail of a mammal where one ring of scales that extends entirely around the tail is succeeded, posteriorly, by other rings.

antebrachium. Forearm, between wrist and elbow joints.

anterior. Of, or pertaining to, or toward the front end.

anterior nares. Anterior openings of the nasal passages in the skull.

antero-internal fold. A fold in the structure of a molar tooth, evident on the occlusal surface and on the anterior and medial side of the tooth.

antitropical. Found in both hemispheres but not in equatorial regions.

antler. A branched bony head ornament found on deer, covered with skin (velvet) during growth, and shed annually.

aquatic. Inhabiting or frequenting water.

arboreal. Inhabiting or frequenting trees. Contrasted with fossorial, aquatic, and cursorial.

auditory bullae. The bony capsules, one on each side of the skull, enclosing the middle ears.

Austroriparian Biotic Province. One of the seven biotic provinces in Texas, encompassing the pine and hardwood forests of the eastern Gulf coastal plain.

autosomal. Pertaining to a chromosome other than a sex chromosome.

backcross. A cross between a hybrid and one of its parents.

baculum. A bone in the penis of certain mammals.

Balconian Biotic Province. One of the seven biotic provinces in Texas, encompassing the central Hill Country region.

baleen. Whalebone; the cornified epithelial plates suspended from the upper jaws of mysticete whales.

beam. The main trunk of an antler.

bicolored. Having two contrasting colors.

bifurcate. To divide or fork into two branches.

biodiversity. The diversity and frequency of organisms in a given area.

biogeography. The study of the distribution of different species around the planet and the factors that influenced their distribution.

bioinformatics. The use of computers in solving information problems in the life sciences; mainly, it involves the creation of extensive electronic databases, including those on genomes and protein sequences. Secondarily, it involves techniques such as the three-dimensional modeling of biomolecules and biologic systems.

biological species concept. Groups of actually (or potentially) interbreeding natural populations that are reproductively isolated from other such groups. Reproductive isolation implies that interbreeding between individuals of two species normally is prevented by intrinsic factors.

biome. A complex biotic community covering a large geographic area and characterized by the distinctive life forms of important climax species.

biotic province. A community occupying an area where similarity of climate, physiography, and soil leads to the recurrence of similar combinations of organisms.

bipedal. Pertaining to locomotion on only two legs.

blastocyst. An early embryo consisting of 8 to 16 cells.

blowhole. A hole for the escape of air (external nostril) in the top of the head of a whale or other cetacean.

bony palate. The bony roof of the mouth formed by parts of the premaxillary, maxillary, and palatine bones.

bottomland. Lowlands along streams and rivers, usually on alluvial floodplains, that are periodically flooded.

braincase. That portion of the skull that encloses and protects the brain; the skull posterior to a plane drawn vertically through the anterior margins of the orbits.

breeding season. The time of the year in the reproductive cycle from mating until birth.

brow tine. The first tine above the base of an antler.

browsers. Mammals that feed on tender shoots or twigs of shrubs and trees.

bullae. See auditory bullae.

Bureau of Ocean Energy Management (BOEM). An agency within the US Department of the Interior, formerly known as the Minerals Management Service, responsible for leasing areas of the outer continental shelf for conventional and renewable energy resources.

burrow. A tunnel excavated and inhabited by an animal.

cache. The process and storage place that a mammal uses to collect, hide, and store food.

calcar. A spur (of cartilage or bone) that projects medially from the ankle in many bats.

centromere. A special region of a chromosome to which the spindle fiber is attached during cell division.

Chagas' disease. An acute and chronic protozoan disease of humans caused by the hemoflagellate Trypanosoma cruzi. Also known as trypanosomiasis.

cheek teeth. Collectively, the premolars and molars or any teeth posterior to the position of the canines.

Chihuahuan Biotic Province. One of the seven biotic provinces in Texas, encompassing the Trans-Pecos region, excluding the Guadalupe Mountains.

chiroptorium. A fabricated auditorium designed to replicate the cave-like conditions necessary for roosting bats.

chromosome. A deeply staining, DNA-containing threadlike structure in the nucleus of a cell that carries the linearly arranged genetic units.

cingulum. An enamel shelf, frequently with cusps, that borders one or all margins of an upper tooth. A cingulid is its counterpart in the lower tooth.

circular overlap. A phenomenon whereby a chain of contiguous and intergrading populations (or subspecies) curves back until the terminal links overlap with each other and behave like good (noninterbreeding) species.

cladistics. A method of developing phylogenies based upon the branching sequences of evolution.

classification. The assignment of groups to taxa.

clavicle. A ventral bone of the pectoral girdle, reduced or absent in many mammals. The collarbone in humans.

claw. The most common form of digital keratinization found in mammals; usually long, curved, and sharply pointed.

colonial. Pertaining to a group of organisms of the same kind living in close association, for example, colonial bats living in a cave.

concealing coloration. Protective coloration facilitating concealment.

concolor. Of uniform coloration.

condylobasal length. A measurement of the skull taken from the front of the base of the incisor teeth to the back of the rounded condyles that border the large opening at the back of the skull.

condyloid process. Point of articulation with the mandibular fossa of the temporal bone. Same as mandibular condyle or process.

conservation easement. A legally binding restriction placed on a piece of property to protect its associated resources, most commonly through an agreement between a landowner and land trust or unit of government designed to limit certain types of uses or prevent development from taking place on the land in perpetuity while the land remains in private hands.

Conservation Reserve Program. A voluntary government program established in 1985 that offers financial assistance to farmers to establish approved cover on highly erodible cropland or pastureland.

conspecific. A condition in which populations or specimens are not sufficiently distinct to be considered separate species.

continental shelf. The term used for the region adjoining the coastline of a continent where the ocean is no more than a few hundred meters deep.

continental slope. The term used for the region where the continental shelf breaks with increased steepness and descends toward the deep ocean floor.

continuous estrus. Situation in which females are receptive to males throughout the year and mating may induce reproductive and hormonal changes.

coprophagous. Feeding on dung or excrement.

copulation. Coitus; the union of male and female reproductive organs to facilitate reception of sperm by the female.

copulation plug. A plug of coagulated semen found in the vagina after copulation. Found only in certain mammalian species. Same as vaginal plug.

coronoid process. The projection of the posterior portion of the dentary that is dorsal to the mandibular condyle.

cosmopolitan. A term used to describe the range of an animal that extends across all or most of the world in appropriate habitats.

coterie. A family group consisting of a male, several females, and their young.

countershading. Coloration of an animal with parts normally in shadow being light or parts normally illuminated being dark.

crepuscular. Active during the twilight periods of dusk and dawn.

crown. The portion of a tooth extending above the gum line.

crown–rump length. The measurement of the total length of an embryo from tip of snout to end of body.

cursorial. Pertaining to running. Cursorial locomotion is running locomotion.

cusp. A point, projection, or bump on the crown of a tooth, usually distinguished by a particular name, such as "hypocone."

delayed development. Found in some Neotropical bats and characterized by a slowing down of the growth rate of the embryo following implantation.

delayed fertilization. An adaptation of certain species of hibernating bats in which mating occurs in late summer but fertilization does not occur until the following spring.

delayed implantation. Phenomenon found in most temperate species of the Mustelidae and several other kinds of mammals in which implantation of the embryo, along with subsequent growth, is delayed for several months.

demography. The statistical study of populations with respect to natality, mortality, migratory movements, age, sex, and other factors.

den. A cave, hollow log, burrow, or other cavity used by a mammal for shelter.

dental formula. A brief method for expressing the number and kind of teeth of mammals. The abbreviations I (incisor), C (canine), P or Pm (premolar), and M (molar) indicate the kinds in the permanent dentition. The numbers of teeth in each jaw are written in pairs, like a fraction, with the figure in front of the diagonal line indicating the number in the upper jaw and that after the line indicating the number in the lower jaw. The dental formula of an adult coyote is I 3/3, C 1/1, Pm 4/4, M 2/3 × 2 = 42.

dentary. One of the two bones (left and right side) that form the mandible (lower jaw) of mammals.

dentition. The teeth, considered collectively, of an animal.

description. A statement of characters and supplementary information that accompanies the naming of a new taxon.

diagnosis. A statement of the characters that serve to distinguish a taxon from similar or closely related taxa.

diastema. A space between adjacent teeth. For example, the space between incisors and premolars in species lacking canines.

diestrous. Pertaining to mammals that have two estrous cycles each year.

digit. Any finger or toe.

dimorphism. Occurrence of two distinct morphological types in a single population.

diploid. Having a double set of chromosomes (2N); the normal chromosome number of cells (except for mature germ cells) in any individual derived from a fertilized egg.

disjunct population. A population of a species that is separated geographically from the main range of the species.

dispersal. The permanent emigration of individuals from a population.

diurnal. Active by day, as opposed to nocturnal.

dorsal. Pertaining to the back or upper surface.

dorsal fin. In mammals, a middorsal projection of fibrous connective tissue found only in certain cetaceans.

echolocation. Sonar; the process of locating objects by emitting sound pulses and receiving and identifying the echoes of those sounds reflected by the objects; used by most bats and cetaceans.

ecotone. A zone of intermediacy between ecological communities.

ectoparasite. A parasite on, or coming in direct contact with, the external surface of an animal, for example, fleas, lice, and ticks.

edaphic. Pertaining to or influenced by soil.

Edwards Plateau. A region of west-central Texas known as the Hill Country, bordered on the east and south by the Balcones Escarpment and on the west by the Pecos River.

elbow. The joint in the forelimb between the humerus and the radius and ulna.

electrophoresis. A process by which enzymes are separated based on differences in electrical charge. Observed differences between or within species indicate mutation and genetic divergence over long periods of time, thus elucidating the genetic distinctness of organisms.

emigration. The process whereby individuals move away from a population.

enamel. Extremely hard outer layer on the crown of a tooth, consisting of calcareous compounds and a small amount of organic matrix. Usually white but sometimes brown, red, or yellow in rodents and some other mammals.

Endangered Species Act. United States law, passed in 1973 and subsequently amended, that regulates the capture, possession, and sale of threatened and endangered species of animals and plants.

endemic. Pertaining to a mammal that occurs only in a certain region.

epidemic. The term used to describe a widespread occurrence of an infectious disease in a community at a particular time.

epipelagic. The term used to describe the uppermost layer of an ocean or sea, generally considered to be waters of a depth less than 200 m that receive enough sunlight to allow photosynthesis.

estivate. To pass the summer or dry season in a dormant condition. The same as aestivate.

estrous. A period of time when female mammals may accept males and mating occurs; specifically, when ovulation occurs. At this time, the pituitary output is predominantly luteinizing hormone, and the newly formed corpus luteum is producing large quantities of progesterone. In vaginal smears, the cells are cornified.

estuary. A river mouth where tidal action brings about a mixing of salt and freshwater.

eurythermic. Tolerating a wide variation in temperature.

exotic. An animal introduced from a foreign country; nonnative.

extirpate. To destroy, make extinct, or exterminate.

extralimital. A term used for occurrences outside a given limit of geographic distribution or zoogeographic area. This can be due to accidental wanderings or human introduction.

F1 hybrid. The offspring resulting from the cross between parents of different races or species.

F2 hybrid. The progeny produced by intercrossing F1 individuals.

femur. The single bone of the upper (proximal) portion of each pelvic limb.

feral. Pertaining to formerly domesticated animals now living in a wild state.

ferruginous. Pertaining to or containing iron and resembling iron rust in color.

fetus. The unborn offspring of viviparous mammals in the latter stages of development.

fibula. The lateralmost of the two bones in the lower (distal) portion of each pelvic limb.

fisheries bycatch. A term used to describe the incidental capture and mortality of nontarget marine animals during fishing.

flippers. Feet fully adapted for an aquatic life; digits elongate and fully webbed.

flukes. Lateral projections of a whale's tail, supported entirely by fibrous connective tissue (no skeletal support).

foraging. The process of wandering in search of food.

foramen (plural, foramina). Any opening, orifice, or perforation, especially through bone, through which nerves or blood vessels pass.

foramen magnum. The large opening at the back of the skull through which the spinal cord passes.

forbs. Herbaceous plants other than grasses or sedges.

fossorial. Pertaining to life under the surface of the ground; adapted for digging.

fragmentation. Division of a large piece of habitat into a number of smaller, isolated patches.

fulvous. Tawny or dull yellow.

fundamental number (FN). The total number of chromosome arms, exclusive of the sex chromosomes, in a diploid cell.

fur. Dense underhair with definitive growth; serves primarily for insulation.

furbearer. A category of mammals harvested for direct commercial use and sale of hides and pelts; includes most small and large carnivores.

GAP. The acronym used to refer to the Gap Analysis Program of the US Geological Survey. Gap analysis is a proactive approach to protecting biodiversity; it seeks to identify gaps between land areas that are rich in biodiversity and areas that are managed for conservation.

gene pool. The total genetic information possessed by the reproductive members of a population.

generalist. A species with broad preferences of food, habitat, or other factors.

genetic species concept. Groups of genetically compatible interbreeding natural populations that are genetically isolated from other such groups. Genetic isolation implies that each species is genetically distinct from other species and that the integrity of the respective gene pools is maintained.

genus. A category within a taxonomic family, consisting of one or more generally similar species. The name of a genus is called the generic name.

gestation period. The length of time from fertilization until birth of a fetus; the period of pregnancy.

glans penis. Sensitive distal portion of the penis.

global warming (or climate change). An increase in the average temperature of the earth's atmosphere, especially a sustained increase sufficient to cause climatic change.

GPS (global positioning system). An instrument for determining precise latitude and longitude of places on the Earth's surface.

granivorous. Feeding on grains or seeds.

gravid. Pregnant.

grazers. Mammals that feed on grass and other herbage by cropping and nibbling.

gregarious. Pertaining to social animals that live in groups or herds.

guard hairs. Outer coat of coarse, protective hairs found on most mammals.

habitat. The kind of environment in which a species or organism is normally found.

hallux. The first (medial) digit of the hind foot (big toe).

herbaceous. Resembling or pertaining to an herb, which is a seed plant that lacks a persistent woody stem aboveground and dies at the end of the season.

herbivore. An animal that consumes plant material as the primary component of its diet.

hibernacula. Winter shelters where animals pass the winter in an inactive (torpid or dormant) state.

hibernation. Of an animal, torpidity, especially in winter; the body temperature approximates that of the surroundings; the rate of respiration and the heartbeat ordinarily are much slower than in an active mammal.

hispid. Rough with bristles, stiff hairs, or minute spines.

home range. The area that a mammal occupies during the course of its life, exclusive of migration, emigration, or unusual erratic wanderings.

homing. The tendency of animals to return to their home area when experimentally displaced to another area.

hoof. The digital keratinization in ungulate mammals, a horny sheath completely encasing the tip of a phalanx and usually providing the animal's only point of contact with the substrate.

horn. Structure projecting from the head of a mammal and generally used for offense, defense, or social interaction. Cattle, sheep, Old World antelopes, and other members of the family Bovidae have horns formed by permanent, hollow, keratin sheaths growing over bone cores.

host. The organism parasitized by a parasite.

humerus. The single bone in the upper (proximal) portion of each pectoral limb.

hybrid. The offspring resulting from a cross between individuals of two species.

hybridization. The mating of individuals from different species or subspecies.

hydrophone. A microphone designed for use underwater to record or listen to underwater sound.

immigration. The process whereby individuals move into a population.

implantation. The attachment of the embryo to the uterine wall of the female mammal.

incisor. The front or cutting teeth between the canines.

infraorbital opening. An opening in the skull through the zygomatic process of the maxilla (in front of the orbit to the side of the rostrum).

infrared photography. Photography that uses thermal imaging cameras to detect radiation in the infrared range and produces images of that radiation called thermograms.

inguinal. Pertaining to or in the region of the groin.

insectivorous. Eating insects; preying or feeding on insects.

interfemoral membrane. In a bat, the fold of skin stretching from hind legs to tail.

interorbital breadth. A measurement of the skull taken at the least diameter of the frontal bones between the orbital openings (also interorbital constriction).

interparietal. An unpaired bone on the dorsal part of the braincase between the parietals and just anterior to the supraoccipital; absent in some mammals.

isolated population. A population that is separated by some sort of barrier from the main body of the species.

IUCN. Acronym for the International Union for the Conservation of Nature, founded in 1964, which is the world's main authority on the conservation status of species. The IUCN Red List of Threatened Species (also known as the Red List) is the world's most comprehensive inventory of the global conservation status of biological species.

jugal. The bone that forms the central section of the zygomatic arch and is located between the zygomatic process of the maxilla and the squamosal.

juvenile. An individual that is physiologically immature or undeveloped. In mammals, juveniles often have distinctive pelage coloration and texture.

juvenile pelage. The type of pelage characteristic of a juvenile of a species.

Kansan Biotic Province. One of the seven biotic provinces in Texas, encompassing the plains region in the northwestern and western areas of the state.

karyotype. An arrangement of chromosomes of a cell according to shape, centromere position, and number; used to aid in identification of species and subspecies within a species.

knee. The joint in the pelvic limb between the femur and the tibia and fibula.

known age. Age established for individual based on observation of birth or other equally reliable criteria.

labial shelf. A thin, narrow, horizontally flattened projection of enamel extending along the side of a tooth closest to the lips.

lacrimal bone. A small bone in the anterior wall of each orbit.

lactating female. A female mammal that is producing milk (nursing young).

lactation. Production of milk by the mammary glands.

litter. The set of young born of a female mammal following a pregnancy.

litter size. The number of young delivered by a female from one pregnancy.

Llano Estacado (Staked Plains). Geographic area in the Texas Panhandle. This geological formation is a large mesa that is an extension of the Southern Plains region.

loph. A transverse ridge of enamel across the occlusal (crushing) surface of a tooth.

mammary gland (plural, mammae). Milk-producing gland unique to mammals. Its growth and activity are governed by hormones of the ovary, uterus, and pituitary.

mandible. The lower jaw; in mammals, composed of a single pair of bones, the dentaries.

mandibular process or condyle. The knob by which each mandible articulates with the skull.

mandibular symphysis. The suture between the paired bones of the lower jaw.

Marine Mammal Protection Act (MMPA). The statute enacted in 1972 by the US Congress to protect marine mammals and their habitat. Mammals covered by the act include whales, dolphins, seals, sea lions, walruses, and polar bears.

mast. Collectively, nuts that serve as food for hogs, squirrels, and other mammals.

mastoid breadth. A measurement of the greatest width across the skull between the two mastoid processes.

maxilla (maxillary bone). One of a pair of bones that forms part of the rostrum, palate, and zygomatic process and bears all upper teeth except the incisors.

maxillary tooth row. A measurement of the alveolar distance from the anterior border of the anterior molar to the posterior border of the posterior molar.

melanistic. Having an unusually dark pelage owing to increased amounts of black pigment.

mesic. Characterized by a moderate amount of moisture.

mesoscale. A term referring to the middle scale of landscape sizes between the microscale, <10 ha, and the megascale, >1,000 ha.

metabolic rate. The rate at which an animal's body consumes oxygen.

metabolic water. The water produced as a by-product of metabolism.

metacarpal. Any bone of the hand between the wrist and fingers.

metacentric. Designation for a chromosome with a centrally placed centromere.

metapopulation. A regional population consisting of semi-isolated local populations; literally, a "population of populations."

metatarsal gland. A gland located on the lower outside portion of the hind leg of some mammals, especially artiodactyls. The function of the gland may be to produce an alarm pheromone or to help in regulating the animal's body temperature.

midden. An accumulation of refuse about a dwelling place.

migration. A movement of animals involving a journey to a definite area and a return journey to the area from which the movement arose, often in response to seasonal patterns of resource availability.

milk tooth. Any tooth in the deciduous set of teeth of mammals with diphyodont dentition; replaced by the permanent teeth.

mist net. A net of fine mesh used to capture birds and bats.

mitochondrial DNA. The DNA contained in the mitochondria of a cell; because offspring typically inherit only their mother's mitochondria, mitochondrial DNA is useful in tracing maternal lineages.

molar. Any cheek tooth situated posterior to the premolars and having no deciduous precursor. One of the four kinds of teeth in mammals.

molt. In a mammal, the act or process of shedding or casting off the hair or horns; most mammals shed the hair once, twice, or three times annually.

monestrous. Pertaining to species that have only one period of estrous or heat per year.

monogamous. Consorting with only one mate; opposite of polygamous.

monotypic. Consisting of only one type, for example, a monotypic species has no subspecies.

montane. Pertaining to a biogeographic zone of the mountains.

morphology. A branch of biology that deals with structure and form of an organism at any stage of its life history.

musk. Scent secretion from any one of a variety of special scent glands in many kinds of animals.

muzzle. The projecting part of the head of certain animals, such as dogs, including the mouth, nose, and jaws; the snout.

nail. Flat, keratinized, epidermal, translucent growth protecting the upper portion of the tip of a digit; a nail is a modified claw.

nasals. The pair of bones on the rostrum that form a roof over the nasal passages. Usually situated between the dorsal margins of the premaxillae and maxillae.

Navahonian Biotic Province. One of the seven biotic provinces in Texas, encompassing the Guadalupe Mountains.

nectivorous. Feeding on nectar.

nest. A structure (of grass, leaves, or some other material) built by a mammal for shelter or insulation.

nestling. An individual, generally recently born, that is still confined to a nest.

nocturnal. Active by night, as opposed to diurnal.

nose leaf. A structure on the noses of some bats; ranges from a small, simple flap to a highly complex structure of numerous projections and chambers; believed to aid in echolocation.

occipital bones. The bone surrounding the foramen magnum that bears the occipital condyles.

occipital condyles. The two knobs on either side of the foramen magnum that articulate with the vertebral column.

ochraceous. Reddish yellow.

omnivorous. Pertaining to those animals that eat quantities of both animal and vegetable food.

opposable. Capable of being placed opposite something else; said of the first toe of the hind foot in an opossum in the sense that it can be placed opposite each of the other toes on that same foot.

orbit. The socket in the skull in which the eyeball is situated.

ovary. The female gonad. The site of egg production and maturation.

overhair. The longer hairs of the pelage of a mammal that project above the fur (shorter hairs).

ovulation. The release of an egg (by the ovary) into the oviduct.

ovum. The haploid reproductive cell (gamete) produced by a female of a species; egg.

palate. The bony roof of the mouth.

palmate antler. Antlers in which the distal portions are broad, flat, and lobed.

pantropical. Distributed throughout the tropics.

parapatric. Pertaining to the ranges of species that are contiguous but not overlapping.

paraxonic. Type of foot structure for which the main axis of weight is distributed between a pair of similarly sized digits, as in the Artiodactyla.

parietals. Paired bones on the roof of the skull posterior to the frontal bones.

parturition. Birth.

pectoral. Pertaining to the chest.

pedalfer soil. A soil of humid regions that is rich in aluminum oxide and iron and deficient in carbonates.

pedocal soil. A soil of semiarid and arid regions that is rich in calcium carbonate and lime.

pelage. Collectively, all the hairs on a mammal.

pelagic. A term used for the water in the open ocean that is neither close to the bottom nor near the shore.

pelvic. Pertaining to the hip girdle.

penis. The intromittent organ that the male mammal inserts into the vagina of the female for the purpose of insemination.

permanent teeth. Teeth in the second of the two sets of dentition in diphyodont mammals, succeeding the milk, or deciduous, teeth.

pes. The hind foot. Collectively, the tarsals, metatarsals, and phalanges of the pelvic limb.

pest. A destructive or obnoxious animal that annoys or causes harm or damage to some human made or supported object or activity.

phalanx (plural, phalanges). Any one of the distal two or three bones in each manual and pedal digit.

phylogenetic analysis. An analysis of the evolutionary history of an organism or groups of related organisms.

phylogenetic species concept. A species is the smallest diagnosable cluster of individual organisms within which there is a parental pattern of ancestry and descent. This concept implies that each species is a member of a monophyletic clade to the exclusion of other species.

phylogenetic systematics. The type of systematics practiced in the field of cladistics.

phylogeny. The evolutionary history of an organism or groups of related organisms.

pinna (plural, pinnae). External ear, the flap located around the external auditory meatus. It gathers sound vibrations and channels them toward the tympanum. Absent in many aquatic and fossorial mammals.

placenta. An apposition or fusion of the fetal membranes to the uterine mucosa for physiological exchange.

placental scar. The scar that remains on the uterine wall after a deciduate placenta detaches at parturition.

plantigrade. Pertaining to walking with the sole of the foot touching the ground, as in bears and raccoons.

pluvial. Characterized by a prolonged period of wet climate.

pollex. The first digit (thumb) of the hand.

polyembryony. A reproductive mechanism by which several young are produced from a single egg fertilized by a single sperm.

polyestrous. Pertaining to species that have three or more estrous cycles each year.

polygamous. Having more than one mate at a time.

population density. A measure of the number of individuals that occupy a given area.

postauricular. Behind the ear.

postnatal. Development that occurs subsequent to birth.

postorbital. Situated behind the socket of the eye (synonym, postocular).

postorbital breadth. Distance across the top of the skull posterior to the postorbital process.

postorbital constriction. Least distance across the top of the skull posterior to the postorbital process.

postpalatal process. A projection along the posterior margin of the palate.

postpartum. The period shortly after giving birth.

postpartum estrous. The condition in which a female comes into estrous again immediately after giving birth.

precocial. Pertaining to young at birth that are capable of moving about and feeding with little parental assistance; opposite of altricial.

predator. A mammal that lives by killing and consuming other animals.

premaxillae. The paired bones at the anterior end of the rostrum that hold the incisor teeth.

premolar. Pertaining to one of the teeth (a maximum of 4 on each side of upper jaw and lower jaw of placental mammals, or 16 in all) in front of the true molars. When canine teeth are present, premolars are behind them; premolars are preceded by deciduous teeth, and in the upper jaw are confined to the maxillary bone.

prey. An animal that is pursued by a predator.

property tax benefit. The opportunity for landowners to claim an exemption on their property if it has been qualified and appraised as agricultural land subject to wildlife management use.

protrusible. In reference to an anatomical part of a mammal that can be thrust out or projected, such as the tongue of an anteater or nectar-feeding bat.

rabies. An acute, encephalitic viral infection; transmitted to humans by the bite of a rabid animal.

rack. The pair of antlers on a cervid.

ramus (plural, rami). A bony process extending like a branch from a larger bone, especially the ascending part of the lower jaw that makes a joint at the temple.

red tide. The common name for a phenomenon known as an algal bloom (large concentral of aquatic microorganisms) when it is caused by a few species of dinoflagellates and the bloom takes on a red or brown color.

reentrant angle. Inward-pointing angle along the margin of a cheek tooth.

reentrant fold. Invagination along the margin of a cheek tooth.

reproductive isolation. The mechanisms that isolate one species reproductively from others.

riparian. Associated with the bank of a natural watercourse, such as a river or stream.

roosting site. A perch or a resting place where an animal will light, sit, or rest during the day or evening. Often used in reference to bats perching in a cave, building, or tree.

root. The portion of a tooth below the gum line that fits into the socket (alveolus).

rostrum. The facial region of the skull anterior to a plane drawn through the anterior margins of the orbits.

rumen. The first compartment of the stomach of a ruminant; here food is collected and returned to the mouth as cud for chewing.

ruminant. Any even-toed ungulate (hoofed) mammal that chews a cud and has a complex three- or four-chambered stomach.

russet. Yellowish brown, light brown, or reddish brown.

rutting season (or rut). Season when mating occurs; particularly applied to deer and other artiodactyls.

saggital crest. A median, longitudinal bony ridge on top of the braincase.

salivary. Pertaining to the secretion of saliva.

salivary glands. Glands responsible for the secretion of saliva.

saltatorial. Adapted for locomotion by leaping.

savannah. A grassland containing scattered trees and drought-resistant undergrowth.

scat. Mammal feces or droppings.

scent glands. Sweat, sebaceous, or a combination of these two gland types modified for the production of odoriferous secretions.

scent marking. The behavioral process by which a mammal intentionally leaves an olfactory indication of its presence in its environment, normally accomplished by deposition of glandular, odoriferous secretions.

scent post. A place or object where a mammal intentionally leaves an indication of its presence in an environment, as described in "scent marking."

scutes. Dermal plates that collectively make up the carapace of an armadillo.

seasonal migration. Movements of individuals, groups, or populations of animals in response to seasonal patterns of resource availability or other factors.

seasonal monoestry. A breeding cycle, typically seen in tropical bats, in which births occur over a spread-out period depending on seasonal conditions such as the rainy season.

sebaceous gland. A gland, arising in association with a hair follicle, that produces and secretes a fatty or oily substance.

sedentary. Pertaining to animals that move about very little.

semiaquatic. Pertaining to mammals that are partially, but not fully, adapted to life in water, for example, otters and beavers.

semifossorial. Pertaining to mammals that are partially, but not fully, adapted for life underground, for example, ground squirrels and badgers.

sex chromosome. Either member of a pair of chromosomes responsible for sex determination; in mammals, the X chromosome or Y chromosome.

sexual dimorphism. The condition that exists when there is an externally apparent difference other than external genitalia between the males and females of a particular species.

sign. Any indication of an animal's presence, such as footprints, scats, burrows, and runways.

species. Groups of actually (or potentially) interbreeding natural populations that are reproductively isolated from other such groups. Reproductive isolation implies that interbreeding between individuals of two species normally is prevented by intrinsic factors.

sperm storage. The situation in some species of mammals in which females do not ovulate until long after they have been inseminated but are able to store viable sperm in the uterus for several months.

stenothermic. Able to tolerate only small variations in temperature.

steppe. Vast tract of land that is generally level and without forests.

subadult. An individual, generally smaller than an adult, that may be a young of the year and may or may not be in breeding condition.

submaxillary gland. A large salivary gland located below the mandible on each side of the jaw.

submetacentric. Designation for a chromosome in which the centromere is nearer one end than the other.

subspecies. Geographically defined aggregate of local populations that differs taxonomically from other such subdivisions of the species.

subtropical. A climatic zone characterized by hot, usually humid summers and mild to cool winters.

supraoccipital. The dorsal element of the occipital bone located above the foramen magnum and the occipital condyles.

sympatric. Pertaining to two or more populations that occupy overlapping geographical areas.

symphysis. A growing together of bones originally separate, as of the two pubic bones or the two halves of the lower jawbone. Also, a line or junction thus formed.

synchronous monoestry. A breeding cycle, typically seen in temperate bats, in which births occur over a period of as little as 2 weeks in a given species at a particular location.

tactile. Pertaining to the sense of touch.

Tamaulipan Biotic Province. One of seven biotic provinces in Texas, including the southern part of the state south of a line extending from Del Rio to San Antonio to Corpus Christi.

tarsal bones. Series of bones in the ankle. They are distal to the fibula and tibia and proximal to the metatarsals.

tarsus. The ankle.

taxonomy. The science of classifying organisms.

temporal ridge. One of a pair of ridges on the top of the braincase of many mammals.

terrestrial. Referring to animals that live on land as opposed to living in the water.

territory. An area defended by an individual or group. Behavior associated with the defense of a territory is referred to as territoriality.

testis (plural, testes). Gonad of the male. The organ of sperm formation.

Texan Biotic Province. One of seven biotic provinces in Texas, representing a broad transitional region between the hardwood and pine forests of extreme eastern Texas and the grasslands of the western part of the state.

tibia. More medial (and usually larger) of the two bones between the knee and ankle in the lower hind limb. The shin bone.

tine. A spike or prong on an antler.

torpid. Without most of the power of exertion; dormant. A ground squirrel is torpid when it is hibernating.

tragus. The fleshy projection located in the lower portion of the ear of most bats.

trail. A pathway created by repeated use by animals.

trap line. A line of traps placed at regular or irregular intervals to secure specimens for identification, study skins, or autopsy purposes.

trap-night. One trap set for one night.

tricolored. Having three colors; said of hair on the back of a mammal when the hair has three bands, each of a different color.

tularemia. A bacterial infection of wild mammals (particularly rodents and lagomorphs) caused by Pasteurella tularensis; it can be transmitted to humans and some domesticated animals.

tympanic bullae. See auditory bullae.

type locality. The place where the type specimen (holotype) of a species or subspecies was collected.

ultrasonic. Pertaining to vibrations and sound waves with frequencies above the range audible to the human ear (generally greater than 20,000 hertz).

underfur. The short hair of a mammal; in temperate and boreal climates the underfur ordinarily is denser (made up of more hairs) than the longer and coarser overhair.

underpart. The underneath (ventral) side of an animal (not the back or sides), as of a wood mouse with white underparts.

ungulate. A mammal having hooves, not claws.

unguligrade. Hoofed or having a foot structure in which only the unguis (or hoof) is in contact with the ground.

unicuspid. Having a single cusp.

unusual mortality event. A part of the Marine Mammal Protection Act referring to a stranding that is unexpected, involves a significant die-off of any marine mammal population, and demands immediate response.

upperpart. The top (dorsal) surface and all of the sides (not belly, chest, or throat) of an animal, as of a wood mouse with reddish brown upperparts.

uropatagium. The interfemoral membrane of a bat; the fold of skin that stretches from the hind legs to the tail.

uterus. In female mammals a muscular expansion of the reproductive tract in which the embryo and fetus develop; opens externally by way of the vagina.

vagina. That portion of the female reproductive tract that receives the male's penis during copulation and through which the fetus passes at parturition.

vaginal plug. A plug of coagulated semen found in the vagina after copulation; found only in certain mammalian species. Same as copulation plug.

vector. An agent, such as an insect, capable of mechanically or biologically transferring a pathogen from one organism to another.

vegetative canopy. The total mass of plant life that occupies a given area, such as a canopy of trees covering a streambed.

velvet. The skin covering a growing antler.

vibrissae. Long, stiff hairs that serve primarily as tactile receptors.

volant. Flying or capable of flying.

volplane. To glide.

webbed. Having a membrane or fold of skin between digits.

wetland. Areas inundated or saturated by surface or ground water at a frequency and duration sufficient to support a prevalence of vegetation typically adapted for life in saturated soil conditions.

wildlife (big game) ranching. The intentional raising of wildlife, especially ungulates, for any purpose, including hunting. Domestic livestock may be raised simultaneously with game on a big game ranch.

wing. A forelimb modified for sustained flight; among mammals, found only in bats.

wool. Hair or underhair with angora growth; serves primarily for insulation.

wrist. The joint between the manus, or hand, and the rest of the forelimb.

xeric. Characterized by a dry, desert-like climate.

young of the year. General age description for an animal that was born in the most recent breeding season and is <1 year old. Frequently used when it is difficult to assign individuals to more precise age categories or when a collective term is needed for this group of young animals.

zygomatic arch. An arch of bone in the skull that encloses the orbit and temporal fossa laterally and is formed by the jugal bone and processes of the maxilla and squamosal.

zygomatic breadth. A measurement of the skull representing the greatest breadth across the zygomatic arches.

zygomatic process. The projection of the maxilla that forms the anterior portion of the zygomatic arch.

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From The Mammals of Texas, Seventh Edition by David J. Schmidly and Robert D. Bradley, copyright © 1994, 2004, 2016.  Courtesy of the University of Texas Press.

Natural Science Research Laboratory