Sea urchins and their relatives.
The study of the relationship between organisms and the environment
The study of the relationship between the morphology (form) of an organism and its environment and ecology.
A local biological community and its pattern of interaction with its environment.
Out of place; in an abnormal position or location
Ectothermy / Ectotherm / Ectothermic
The condition of acquiring most heat energy for metabolic process from the external environment; e.g., by basking. Thus, ecotherm, ectothermic. Compare endothermy.
The process of eliminating waste material from the digestive tracts as feces.
Material such as glass and fragmented rock thrown out of an impact crater during its formation.
Embryo / Embryonic
The stage of a vertebrate in early development, before birth or hatching. Thus, embryonic.
The scientific study of embryos; the study of the development of an organism from a fertilized egg.
A form of calcium phosphate found in teeth.
Endemic / Endemism
Relating to a native species or population that occurs in a very restricted range. Thus, endemism.
A sediment in-fill of the brain cavity
The cavity in the skull for the brain and associated soft parts.
Occurring within the body; relating to or involving internal processes.
The cartilaginous, and bony skeleton, excluding and part of the skeleton that is of dermal origin. Compare exoskeleton
A fibrous connective tissue that coats the internal surface of bones and that has the potential to form new bone material.
Endothermy / Endotherm / Endothermic
The ability to regulate body temperature through the body\'s own metabolism. Thus, endotherm, endothermic. Compare Ectothermy
Not providing definite evidence or conclusions; not clearly defined; uncertain; puzzling.
Another spelling of aeolian: caused by the wind.
A protrusion on the surface of a bone, above its condyle (rounded projection).
The outer layer of skin, external to the dermis.
The end portion of a long bone.
Epipodium / Epipodial
The region of the rear part of the foot, or the bones of this area, Thus epipodial
Relating to or composing the epithelium.
A type of animal tissue consisting of cells that are tightly packed together with little material between them; the tissue covering the outer surface of the body and also certain internal surfaces of body cavities.
Small bone edging the frill on the skull of ceratopian dinosaurs.
A combination of various processes in which the materials of the earth\'s surface are loosened, dissolved, or worn away, and then are transported from one place to another by natural agents.
A cliff or steep slope produced by erosion or faulting, typically separating two level or less sloped areas.
The land areas of Europe and America which were joined for much of the Mesozoic Era.
The land areas of Europe and Asia joined as they are today.
A reptile group, exclusievly aquatic and now extinct (e.g. plesiosaurs and ichtyosaurs) characterised by a small opening high up on the side of the skull behind the eye socket.
The process of turning inside out in relation to the normal position.
The processes and patterns of change through time; in living organisms, descent with modification.
To change in form or appearance over successive generations.
Occurring outside the body; relating to or involving external processes.
Hard outer supporting structures other than bone or cartilage; produced by the epidermis; e.g., scales, armor plates, teeth, hoofs, or nails, or feathers. Compare endoskeleton
An area where bare rock is exposed to the erosive action of the weather.
In existence; currently living; not extinct
A muscle which straightens a joint, as opposed to a flexor muscle.
Not in existence as a group; no longer living.
The death of every member of a species or taxonomic group without any descendants, causing the worldwide disappearance of the group. See also true extinction, pseudoextinction.