1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48

and Gram's stain, which can detect keratin, are also useful.
Positive controls may include hard tissues from vertebrate and invertebrate fossils from the same localities, as well as skeletal material from fish and amphioxus. Additional controls could involve conodonts that are subjected to light etching instead of decalcification, and the staining of undecalcified elements. The method does not work well on elements that are still embedded in matrix.
This technique makes it possible to localise organic residues to defined tissues in the conodont that are still in a natural position. The stain is not a surface deposit, but soaks into the hyaline tissue and leaves the albid tissue that is exposed on the surface unstained.
Although molecules such as collagen are widespread in the Animal Kingdom, it is unlikely that any of the stains are in fact specific for particular protein residues in the fossil material. They are simply deposited in regions of high organic content. Nevertheless, the presence of hydroxyproline in many species of unaltered conodont element is an effective demonstration that hyaline tissue is high in collagen in the original unfossilised state, and therefore unlikely to be a form of vertebrate enamel. No organic residues appear to be present in the albid tissue, and this is therefore unlikely to be a form of vertebrate bone.

Kemp, A. & Nicoll, R.S. 1996. A
histochemical analysis of biological
residues in conodont elements. Modern
Geology 20. 287-302 [reprinted in MG
21, 197-213 with 2 colour plates]. Savage, N.M., Lindorfer, A. & MacMillen,
G.E. 1990. Amino acids from Ordovician
conodonts. Courier Forschungsinstitut
Senckenbverg 118, 267-275.
J. ALDRIDGE, Professor of Palaeontology, Head of Department, Department of Geology, The University, Leicester LE1 7RH, U.K.
Phone: 0116 252 3610
Fax: 0116 252 3918
E-mail: ra12@leicester.ac.uk

Palaeobiology in the UK does pretty well at the moment. Ivan Sansom and Phil Donoghue have both just been given Lectureships at Birmingham, and we have appointed Sarah Gabbott to a Lectureship in Leicester. Derek Briggs was elected FRS. As far as my current students go, Kim Freedman is in the very final stages of writing up(look out for her taphonomic study of Jamoytiusin Palaeontology) and Steph Barrett is getting some interesting new results out of sectioning conodonts. I have a new student starting in September, but he will be working on acritarchs.

IMAGE imgs/I.I.20.web29.jpg

Papers of interest:
Donoghue P.C.J. & Chauffe, K.M. 1998.
Conchodontus, Mitrellataxisand
Fungulodus: Conodonts, fish or both?
Lethaia31: 283-292.
Donoghue P.C.J., Purnell, M.A. & Aldridge,
R.J. 1998. Conodont anatomy, chordate
phylogeny and vertebrate classification.
Lethaia. 31:211-219.
Donoghue P.C.J.,Forey, P.L. & Aldridge, R.J.
2000. Conodont affinity and chordate
phylogeny. Biol. Rev. 75, 191-251.

Fascinating stuff! - ed.

Mark PURNELL, Department of Geology, The University, Leicester LE1 7RH, U.K.

Is now on the permanent staff at Leicester.

Purnell M.A. 1999. Scenarios, selection, and the ecology of early vertebrates. In Major Events in Early Vertebrate Evolution: Palaeontology, Phylogeny and Development. A joint Systematics Association / Natural History Museum meeting 8-9 April 1999, p. 25.

****************** MORE NEWS
* * * *

Barbara J STAHL

Handbook of PaleoichthologyVolume 4.
Chondrichtyes III Holocephali

Where to order

Verlag Dr Friedrich Pfiel
Wolfratshauser Str. 27. D-81879
Ph: 49 89 7428270, fax: 49 89 7242772. E-mail: 100417.1722@compuserve.com


The Encyclopedia of
edited by Dr Ron SINGER
Published by Fitzroy Dearborn Publishers. 2
volumes; 1700 p. Chicago.
ISBN 1-884964-96-6

includes papers on fossil fish by several of
our group - e.g., Burrow, Gagnier, Janvier,
Kemp, Long, Sansom, Turner, Young