Obligate or Obligatory
Restricted or limited to a single mode of behavior or to specific environmental condition; e.g., an obligate quadruped walks only on four legs, never on two.
Oblitum [Nomen Oblitum]
According to the Code, a descriptive term meaning forgotten name; not used in this edition of the code, but formerly used in Article 23b in force between 6 November 1961 and 1 January 1973; nomina oblita (pl.).
Describes the flange of bone connecting the ischium to the pubis in Predentatans. Thyreophoroids (armored dinosaurs) lacked this prong
1. Relating to the lower back of the skull.
2. The compound bone forming this area.
The lower rear portion of the skull.
The grinding surface of a tooth
The contact pattern of the bite; the manner in which the teeth close together.
A projection on the proximal end of the ulna (lager bone of the forearm or forelimb].
Relating to the nose or the sense of smell, or to nerves or other body parts involved with smelling.
An animal with a diet of both plant and animal food.
Ontogeny / Ontogenous / Ontogenetic
The development history of an individual organism. Thus, Ontogenous, Ontogenetic.
A prefix meaning \\\"egg\\\".
A developing egg cell.
Oogonium [plural] Oogonia
A female germ cell that gives rise to an oocyte (developing egg cell).
The scientific study of eggs.
Oospecies / Oogenus / Oofamily
An identification of organisms by species (genus, family) according to the classification of their eggs or fossilized egg remains.
Describes vertebrae in which the front of the centrum is convex and the rear of the centrum is concave -- so that the front of the vertebra fits into the next vertebra forward like a ball-and-socket joint
Describes a condition where the pubis bones point backward, as in maniraptors and predentatans
Orbit / Orbital
The eye socket; the bony cavity in the skull in which the eyeball is located. Thus, Orbital
A category of animals that includes a variety of similar families
Relating to living beings or material from living beings.
An individual living being; any individual living animal, plant or other life form.
A visible body feature of an organism that functions primarily in social behavior rather than in the life processes of the individual organism; e.g., distinctive coloration that serves to identify this individual as male or female to others of the same species.
The scientific study of birds.
Relating to or resembling bone; bony
1. A small bone or bonelike structure. 2. One of the small bones of the middle ear.
The process of forming bone.
A prefix meaning \\\"bone\\\" or \\\"relating to bones\\\".
Osteoblast / Osteoblastic
An immature bone cell that actively participates in bone formation. Thus, Osteoblastic.
A bone cell.
Any bone imbedded in the skin. Osteoderms include the scutes of crocodiles, the keeled scutes, spines, and tail-club bones of ankylosaurs, and the plates, spines, and gular ossicles of stegosaurs. Their function is usually for protection and display. A bone or bonelike structure embedded in the skin.
A fossil bone that has become completely mineralized.
The scientific study of bones.
Osteopathy or Osteopathology
Disease or injury of the bones.
In a classification of groups of organisms (taxa) the sister group (first outgroup) or another related group (second outgroup etc.) that is compared to the particular group under study (the ingroup).
The upper part of a sedimentary layer that compresses and consolidates the underlying material.
Oviparous / Oviparity
Producing eggs; bearing offspring that develop and hatch in an egg, outside the material body; e.g., modern birds and reptiles. Thus, Oviparity. Compare Viviparous