Definission: A taxon is Extinct when there is no reasonable doubt that the last individual has died. A \r\ntaxon is presumed Extinct when exhaustive surveys in known and/or expected habitat, \r\nat appropriate times (diurnal, seasonal, annual), throughout its historic range have failed \r\nto record an individual. Surveys should be over a time frame appropriate to the taxon’s life cycle and life form.
Definission: overall repetitive or reflective pattern in the body of one individual of this taxon. eg: bilateral symmetry, rotational symmetry, radial symmetry
Definission: an animal that excavates holes or tunnels into soil or benthic sediment to create a space suitable for habitation, temporary refuge, or as a byproduct of locomotion. Inhabited burrows function as a refuge, protecting the inhabitants from predation and environmental extremes. They provide physical support for the digging and feeding activities of the burrow inhabitants. The harsh chemical environment deep in aquatic burrows must be counteracted by active or passive irrigation of burrow water.
Definission: directly or indirectly modulating the availability of resources to other species, by causing physical state changes in biotic or abiotic materials; modifying, maintaining and/or creating habitats
Definission: The marine benthic biome (benthic meaning 'bottom') encompasses the seafloor and includes such areas as shores, littoral or intertidal areas, marine coral reefs, and the deep seabed.
Definission: Drag swimmers use a cyclic motion where they push water back in a power stroke, and return their limb forward in the return or recovery stroke. When they push water directly backwards, this moves their body forward, but as they return their limbs to the starting position, they push water forward, which will thus pull them back to some degree, and so opposes the direction that the body is heading. This opposing force is called drag. The return-stroke drag causes drag swimmers to employ different strategies than lift swimmers. Reducing drag on the return stroke is essential for optimizing efficiency.
Definission: The number of fossil occurrences in the Paleobiology Database (https://paleobiodb.org) that are identified as belonging to a particular taxon or any of its subtaxa.
Definission: Hard framework, internal or external, which supports and protects softer parts of plant, animal or unicellular organism, and to which muscles usually attach in animals, includes skeletons (derived from Lawrence, 2005).
Definission: A compound eye with no separation between the crystalline-cone layer and the retinula, each rhabdom receiving light only from its own corneal lens.
