Michael J. Melchin

Professor, Department of Earth Sciences , St. Francis Xavier University.

 

 

This image shows two specimens of graptolites, fossils of a group of extinct invertebrate organisms. The branching spiral form is Cyrtograptus sakmaricus and the straight form is Pristiograptus nudus. The straight specimen is 4 cm long. These specimens were collected from Bathurst Island in Arctic Canada and they are Silurian in age, approximately 430 million years old.

My research interests are primarily in the areas of Invertebrate Paleontology and Stratigraphy. In particular, my focus is the study of graptolites and their associated carbonate/shale sequences. I am interested in all aspects of graptolites including their biostratigraphy, paleobiology, evolution and systematics.

I received my B.Sc. and M.Sc. degrees at University of Waterloo and my Ph.D. at University of Western Ontario. In addition to my faculty position at St. Francis Xavier University, I am an Adjunct Professor at Dalhousie University, Department of Earth Sciences, and an Adjunct Professor in the Earth Sciences Department at the University of Western Ontario. I am able to supervise graduate theses at any of these three institutions.

Current Research Projects:

Global Analysis of Graptolite Biodiversity Dynamics and Paleonenvironmental Changes Through the Late Ordovician Mass Extinction Event and Early Silurian Cycles of Recovery and Extinction. I am working with colleagues in Canada, the USA, China, Russia, and Europe on quantitative studies of the graptolite biodiversity changes through the Late Ordovician extinction event and subsequent biotic recovery interval. We are sampling and restudying well-known sections from various parts of the world to document the global patterns of biodiversity change and their relationship to variations in paleoclimate and paleoenvironment, as reflected in the sedimentology and geochemistry of the host strata, particularly the stable isotope chemostratigrpahy.

Morphometric, phylogenetic and paleobiological study of uncompressed graptolites from the Cape Phillips Formation. Multivariate statistical techniques will be applied to the morphologic study of these collections which are unique worldwide for their exquisite preservation and stratigraphic coverage. Two such studies have recently been completed as M.Sc. theses under my supervision and papers are currently in preparation.

Graptolite Taphonomy and Population Structure. Layer-by-layer dissolution of graptolite-bearing concretions permits observation of undistorted orientation of graptolite specimens in situ in the sediments through a succession of strata. Numbers, orientation and composition of the graptolites from each layer can be related to lithology of the laminae. The diversity, abundances and sedimentological properties of each layer can then be related to the paleoecological and taphonomic processes that acted on graptolites. Distinct graptolite taphofacies should be recognisable that can be related to these processes. In addition, the graptolite specimens isolated by layer-by-layer dissolution can be studied and compared for short-term changes in individual species or assemblage composition.

Treatise of Invertebrate Paleontology. I am currently working as one of the co-ordinating authors on the 3rd edition of the graptolite volume of the Treatise of Invertebrate Paleontology. In addition to summarizing the previous work done related to the systematics, phylogeny, paleobiology and biostratigraphy of graptolites and related taxa, this work is requiring considerable new research, especially into their phylogeny and systematics.

List of publications.

A useful jumping point into the paleontological resources on Internet is The Paleonet Pages

Jump back to the St. F.X. Department of Earth Sciences.

Michael Melchin, Professor
Department of Earth Sciences, St. Francis Xavier University
P.O. Box 5000, Antigonish, Nova Scotia, B2G 2W5 Canada
Voice 902-867-5177 FAX 902-867-2457 mmelchin@stfx.ca
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mmelchin@stfx.ca – October, 2007