Glossary: T

Territory Size

The size of the area defended by an individual or a social group against other individuals of the same species or sex, i.e. the size of the territory.

See Also: territorial; territory
tactile

uses touch to communicate

tagmata

the compound body sections of an arthropod resulting from embryonic fusion of two or more segments. Singular is tagma. Having three tagmata or divisions of the body (head, thorax and abdomen) is a synapomorphy of the Insecta.

tagmosis

the functional specialization of segments of the body in metamerically segmented animals, resulting of a subdivision of the body into distinct regions (tagmata).

taiga

Coniferous or boreal forest, located in a band across northern North America, Europe, and Asia. This terrestrial biome also occurs at high elevations. Long, cold winters and short, wet summers. Few species of trees are present; these are primarily conifers that grow in dense stands with little undergrowth. Some deciduous trees also may be present.

talus

Rock debris at the base of a cliff.

taxon

A particular group of organisms of any taxonomic rank. For example, a phylum, a genus, or a species. Plural is taxa.

taxonomy

Referring to the science of hierarchically classifying animals by groups (e.g. genus and species) which share common features and are thought to have a common descent.

See Also: phylogenetic; systematics
teat

the nipple of the mammary gland of a mammal, from which the young extract milk during lactation

tegument

Body covering that is distinct from epithelium.

temperate

that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).

temperate coastal

An aquatic biome including the ocean bottom in coastal areas of temperate regions, to about 1000 m depth.

temperate forest and rainforest

Forests occuring at temperate latitudes (>23.5° N or S latitude). This terrestrial biome is characterized by moderate to large seasonal changes in temperature; rainfall, however, is usually more evenly distributed. Leaves of deciduous trees drop during autumn and winter. Temperate rainforests may experience less seasonal change in temperature.

temperate grassland

A terrestrial biome found in temperate latitudes (>23.5° N or S latitude). Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.

temporary pools

pools of water that are temporary, forming seasonally and typically drying at some point. Also called vernal pools or ephemeral pools.

terai

A 8-24 km (5-15 mile) wide belt of swampy grass jungle generally between the Himalayan foothills and the plains of India. It extends from northeast Uttar Pradesh (India) in the east, through southern Nepal and northwest Bengal (India) to northwest Assam (India) and adjacent parts of extreme southern Bhutan.

terrestrial

Living on the ground.

terrestrial biomes

major land ecosystems characterized by plant associations, examples are grasslands, tundra, or tropical rainforest, etc.

terricolous

living on or in the soil; used of an organism that spends most of its active life on the ground.

territorial

defends an area within the home range, occupied by a single animals or group of animals of the same species and held through overt defense, display, or advertisement

territory

An exclusive area maintained through overt defense or advertisement; the part of the home range of an animal that is protected, by fighting or aggressive gestures, from others of its own kind, during some phase of its life.

test

a shell or hardened outer covering. The hardened skeleton of echinoderms (Phylum Echinodermata, sea stars, sea urchins, sea cucumbers) is called a test.

thanatosis

an anti-predator adaptation in which animals either become temporarily immobile or pretend to be dead so deter predators.

the length of a limb of an adult animal
thorax

The portion of the body between the head and abdomen of certain species that bears whatever legs and wings are present.

threatened

The term is used in the 1994 IUCN Red List of Threatened Animals to refer collectively to species categorized as Endangered (E), Vulnerable (V), Rare (R), Indeterminate (I), or Insufficiently Known (K) and in the 1996 IUCN Red List of Threatened Animals to refer collectively to species categorized as Critically Endangered (CR), Endangered (EN), or Vulnerable (VU).

time to independence

the typical or range of typical lengths of time it takes for a young animal to be able to survive independently of parental care.

torpor

a dormant, inactive state.

torsion

Twisting of the body during development so that the posterior of the body takes a anterior position over the head. Synapomorphy of the Gastropoda.

toxin

a poisonous substance, usually a protein, that is produced by living cells or organisms and causes harm or disease when introduced into the body tissues of other organisms.

tracheae

A system of tubes that allow air to permeate the body of invertebrates. Trachea (singular). Synapomorphy of the Myriopoda+Insecta, convergently found in Onychophora.

tripartite coelom

Coelom pouches out from primitive gut to form three coelomic cavities. Synapomorphy of the Deuterostomia, convergent in the Lophophorates.

See Also: coelom
trochophore larva

a free-swimming marine larva characteristic of most molluscs, certain ectoprocts, brachiopods, and marine worms. This larva locomotes using a preoral circlet of cilia and sometimes a secondary circlet behind the mouth. Synapomorphy of the Trochozoa

tropical

the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.

tropical coastal

An aquatic biome including the ocean bottom in coastal areas of tropical regions, to about 1000 m depth.

tropical deciduous forest

A terrestrial biome similar to tropical rainforest and found at the same latitudes, but rainy and dry seasons are more distinct and the total amount of rainfall is usually less. Most trees are deciduous and drop their leaves during the dry season. Thorny vegetation is sometimes prominent.

tropical rainforest

A terrestrial biome found within 23.5? of the equator in areas where rainfall is abundant (more than 250 cm/year) and the dry season, if any, is brief. Forests are very diverse floristically and structurally; trees sometimes reach great heights. Most trees are evergreen; deciduous species, if present, do not all lose their leaves at the same time of year.

tropical savanna and grassland

A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia.

tropical savanna and grassland

A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia.

savanna

A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.

temperate grassland

A terrestrial biome found in temperate latitudes (>23.5° N or S latitude). Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.

tropical scrub forest

A terrestrial biome similar to tropical deciduous forest, but most trees are small, the dry season is prolonged, and many plant species bear thorns.

tundra

A terrestrial biome with low, shrubby or mat-like vegetation found at extremely high latitudes or elevations, near the limit of plant growth. Soils usually subject to permafrost. Plant diversity is typically low and the growing season is short.

type locality

The locality from which a species or subspecies was first described.