Glossary, literature and web
links
Glossary:
- 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.
- Fossa
- a concave hollow in a bone for receiving a condyle in a joint.
- Gnathostomes - jawed vertebrates
including the Classes; Placodermi, Chondrichthyes, Acanthodii
and Osteichthyes.
- Holocephalans - a group of cartilaginous
fish (Class Chondrichthyes) comprising the extant chimaeras and
rabbitfishes.
- Osteichthyes - the 'bony
fishes'.
- 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.
References:
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.
Links:
Devonian Times: site index
BBC Evolution Weekend: Extinction Files
BBC Sea Monsters
Return to Fossil groups home
page
Websites produced by students
on the MSc
Palaeobiology programme in the Department
of Earth Sciences at the University of Bristol for academic
year 2004-5
