Page 438 - Introduction to Paleobiology and The Fossil Record

DEUTEROSTOMES: ECHINODERMS AND HEMICHORDATES 425

more advanced text with emphasis on taxonomy;
Review questions extravagantly illustrated.)
1 The deuterostomes include two appar-
ently morphologically different groups, References
the echinoderms and hemichordates. What Aldridge, R.J., Hou Xian-Guang, Siveter, D.J., Siveter,
sort of characters could be used to unite D.J. & Gabbott, S.E. 2007. The systematics and
them? phylogenetic relationships of vetulicolians. Palaeon-
2 Crinoids are most common in deep-water tology 50, 131–68.
environments but probably exploited Bottjer, D.J., Hagadorn, J.W. & Dornbos, S.Q. 2000.
much shallower-water environments The Cambrian substrate revolution. GSA Today 10,
during the Paleozoic. When and why did 1–7.
they move to deeper water? Chen Xu, Zhang Yuan-Dong & Fan Jun-Xuan. 2006.
3 Echinoids have a long history. Why did it Ordovician graptolite evolutionary radiation: a
take over 250 myr to develop the buried review. Geological Journal 41, 289–301.
(sand dollars) and burrowing (sea urchin) Clausen, S. & Smith, A.B. 2005. Palaeoanatomy and
biological affinities of a Cambrian deuterostome

life strategies? (Stylophora). Nature 438, 351–4.
4 Graptolites evolved through time by reduc- Delsuc, F., Brinkmann, H., Chourrout, D. & Philippe,
ing their numbers of stipes and developing H. 2006. Tunicates and not cephalochordates are the
more complex thecae. What were the eco- closest living relatives of vertebrates. Nature 444,
logical advantages of this more stream- 85–8.
lined body plan with more elaborate zooid Donovan, S.K. & Gale, A.S. 1990. Predatory asteroids
openings? and the decline of the articulate brachiopod. Lethaia
5 The vetulicolians highlight one of the dif- 23, 77–86.
fi culties of the fossil record, identifying Gupta, N.S., Briggs, D.E.G. & Pancost, R.D. 2006.

definitive characters of phylogentic signifi - Molecular taphonomy of graptolites. Journal of the
Geological Society, London 163, 897–900.
cance in bizarre taxa. Should new higher Jefferies, R.P.S. 1986. The Ancestry of the Vertebrates.
taxa, for example classes of phyla, be British Museum (Natural History), London.
established to accommodate such material Jefferies, R.P.S. & Daley, P. 1996. In Harper, D.A.T. &
or should it be shoehorned into existing Owen, A.W. (eds) Fossils of the Upper Ordovician.
taxa? Field Guide to Fossils No. 7. Palaeontological Asso-
ciation, London.
Jeppsson, L. & Calner, M. 2003. The Silurian Mulde
event and a scenario for secundo-secundo events.
Further reading
Transactions of the Royal Society of Edinburgh:
Berry, W.B.N. 1987. Phylum Hemichordata (including Earth Sciences 93, 135–54.
Graptolithina). In Boardman, R.S., Cheetham, A.H. Kammer, T.W. & Ausich, W.I. 2006. The “Age of
& Rowell, A.J. (eds) Fossil Invertebrates. Blackwell crinoids”: a Mississippian biodiversity spike coinci-
Scientific Publications, Oxford, pp. 612–35. (A com- dent with widespread carbonate ramps. Palaios 21,

prehensive, more advanced text with emphasis on 238–48.
taxonomy; well illustrated.) Kirk, N. 1969. Some thoughts on the ecology, mode of
Clarkson, E.N.K. 1998. Invertebrate Palaeontology and life, and evolution of the Graptolithina. Proceedings
Evolution, 4th edn. Chapman and Hall, London. of the Geological Society of London 1659,
(An excellent, more advanced text; clearly written 273–93.
and well illustrated.) Kozl ´ owska-Dawidziuk, A. 2004. Evolution of retiolitid
Rickards, R.B. 1985. Graptolithina. In Murray, J.W. graptolites – a synopsis. Acta Palaeontologica
(ed.) Atlas of Invertebrate Macrofossils. Longman, Polonica 49, 505–18.
Harlow, Essex, pp. 191–8. (A useful, mainly photo- Paul, C.R.C. & Smith, A.B. 1984. The early radiation
graphic review of the group.) and phylogeny of echinoderms. Biological Reviews
Smith, A.B. & Murray, J.W. 1985. Echinodermata. In 59, 443–81.
Murray, J.W. (ed.) Atlas of Invertebrate Macrofos- Rickards, R.B. & Durman, P.N. 2006. Evolution of the
sils. Longman, Harlow, Essex, pp. 153–90. (A useful, earliest graptolites and other hemichordates. In
mainly photographic review of the group.) Bassett, M.G. & Diesler, V.K. (eds) Studies in Pal-
Sprinkle, J. & Kier, P.M. 1987. Phylum Echinodermata. aeozoic Palaeontology. Geological Series No. 25.
In Boardman, R.S., Cheetham, A.H. & Rowell, A.J. National Museum of Wales, Cardiff, pp. 5–92.
(eds) Fossil Invertebrates. Blackwell Scientifi c Publi- Ruta, M. 1999. Brief review of the stylophoran debate.
cations, Oxford, pp. 550–611. (A comprehensive, Evolution and Development 1, 123–35.