Glossary, literature and web
- Acanthodii - an extinct group of
jawed vertebrates, sometimes called 'spiny sharks', that are
believed to form a sister group to the Osteichthyes.
- 'Bradyodonts' - chondrichthyans with
large crushing tooth plates made up of columnar dentine, which
belonging to the stem-group of the holocephalans.
- Chimaeras - see Holocephalans.
- Chondrichthyes - the 'cartilaginous
fishes' represented today by the elasmobranchs (sharks and rays)
and the holocephalans (chimaeras).
- Condyle - a round process on
a bone where it forms a joint with another bone.
- Epicercal - the
tail (caudal) fin of fishes tapers posterio-dorsally, like in
modern sharks. Generally, this signifies that the notochord or
spine forms the upper margin of the tail fin.
- a concave hollow in a bone for receiving a condyle in a joint.
- Gnathostomes - jawed vertebrates
including the Classes; Placodermi, Chondrichthyes, Acanthodii
- Holocephalans - a group of cartilaginous
fish (Class Chondrichthyes) comprising the extant chimaeras and
- Osteichthyes - the 'bony
- Paraphyletic - Composed
of members which all originated from a single ancestral line,
which is included within the taxonomic group, but where the ancestor
also has (or had) other descendents which are not classified
within that group.
- Polyphyletic - Composed of members that originated,
independently, from more than one evolutionary line.
- Trabecular - porous, as in trabecular
bone which is also known as spongy or cancellous bone.
Benton, M., J. 2000. Vertebrate
palaeontology. Blackwell Science Ltd, Oxford, UK. 54-58.
Janvier, P. 1996. Early Vertebrates.
Oxford monographs on geology and geophysics 33. Oxford University
Press, Oxford, UK. 150-173.
Smith, M., M. & Johanson,
Z. 2003. Separate evolutionary origins of teeth from evidence
in fossil jawed vertebrates. Science, 299, 1235-1236.
Devonian Times: site index
BBC Evolution Weekend: Extinction Files
BBC Sea Monsters
Return to Fossil groups home
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Palaeobiology programme in the Department
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