R-selection / R-strategy / R-strategists
A pattern of reproduction of a given species, generally characterized by early maturation and large production of great numbers of rapidly developing young, a short life span, and negligible parental involvement in the rearing of young; e.g., mosquitoes. Also R-strategy, R-strategists. Compare K-selection
1. The process by which a group of species diverge from a common ancestral form resulting in an overall increase in biological diversity. 2. The occurance of this phenomenon over a relatively short time.
The disintegration of an unstable isotope into a more stable isotope with the production of radiation (energy).
A technique of estimating the age of ancient organic materials (e.g., bone or shell) by measurinr the loss over time of radioactive carbon (carbon-14), which has a precisely known rate of decay; the absorption of radiocarbon in living tissues ceases with death and thus the amount remaining gives an indication of the time elapsed since the death of the organism.
See Radiometric dating.
See Radiometric dating.
Measurement of radioactive decay.
The innermost bone of the foreleg/forearm. The shorter, medial bone of the forearm or forelimb.
Either of the two branches of the lower jaws.
The position of a given level of classification in relation to the levels above and below; e.g., genus is a more general catagory than species but less inclusive than family.
1. A modern bird of prey, such as a falcon, hwak or eagle. 2. A dinosaur described as having cornivorous predatory behaviour similar to that of such birds.
1. Having a flat breastbone. 2. One of a group of birds characterized by a flat breastbone; e.g., the modern ostrich or kiwi.
The fact of one alternate form of a gene tending to be masked by the expression of the other corresponding form (the dominant form).
1. The process of preparing complete individual bones, or an entire or partial skeleton, of an ancient, extonct animal by utilizing the available, fossil material from this animal and, as necessary, filling in the missing, elements with other materials. 2. A bone or skeleton assembled in this manner. See also restoration. 3. A pattern of internal bone growth in which new bone replaces preexisting bone tissues.
Curved backwards (of teeth).
A statement of the approximate age of an object or feature in comparison with some other object or feature, rather than in terms of its age in years. Compare Absolute age.
A device for increasing sound levels by vibrating in sympathy with the source of the sound.
The process of breathing; the exchange of gases between a living organism and its surrounding atmosphere.
1. The process of creating a complete individual model of an acient animal by placing materials that simulate miscles and skin over a skeletal reconstruction of the animal. 2. A sculpture or illustration prepared in this manner.
Small projection on the articular bone forming part of the jaw joint system
Retroversion / Retroverted
In anatomy, the tipping or turning backward of an organ or other body part. Thus, Retroverted
The thick, horney covering of a bird\'s or turtle\'s beak, or a comparable structure at the front of the upper jaw in some dinosaurs. (e.g., hadrosaurids).
Squat, pig-like creatures with a curious hooked beak from the late Triassic Period
High mountain ranges on the sea-floor marking the point where new sea-floor is emerging from the interior of the Earth.
Stiffening of the body following death.
1. Strongly built or formed; sturdy and powerful. 2. Of a method of analysis or inverstigation, likely to produce an accurate inference or likely to resist falsification verified by past results
1. Relating to or located at the rostrum (beak or snout) 2. A bone at the tip of the snout.
Upper jaw bone on ceratopians, in front of the premaxillary bone, that forms the upper part of the beak
The beak or snout of an animal.
Having a rough surface.
1. Feeding by a distinctive process that involves taking in (plant) food quickly, partly digesting it, and thenm bringing it back up to the mouth and chewing it more thoroughly at a later time. 2. An animal that feeds in this manner; e.g., modern cattle ans sheep.