Research Interests

The profusion of life on our planet is astonishing. One expression of this is the sheer number of living species: An average of 23 new organisms have been formally entered into the scientific literature every day of the 236 years since publication of the 10th edition of Linnaeus’ Systema Naturae. Reasonable estimates of the number of species of living organisms yet to be recognized approach 30 million. Fossils expand the total even more. All these organisms are related genealogically (phylogenetically) at some level, and our ability to understand the present diversity of life and its history depends upon a well supported hypothesis about this phylogeny. Constructing such an hypothesis is the central task of systematics, and it will occupy that discipline well into the next century. At issue are not only the phylogenetic relationships among organisms, but also the derivative knowledge that reveals the grand patterns of organic evolution through time (adaptive radiations, mass extinctions, ecological succession, etc.) which in turn inform our understanding of the tempo and mode of evolution and the broad history of our planet.

Within this larger picture, my interests focus on the origin of terrestrial vertebrates and their subsequent diversification in the Late Paleozoic, essentially the first third of tetrapod history. Current research focuses both on the discovery and comprehension of individual fossil tetrapods, and on understanding the broad picture of the early acquisition of tetrapod features that enabled their successful radiation into terrestrial habitats. Presently, in collaboration with John Bolt at the Field Museum of Natural History a series of new and very early tetrapods from sites in Iowa and Illinois are under study. Some of these fossils are exceptionally well preserved and are providing the opportunity to learn about tetrapod structure in ways not previously possible.

Characters are any describable attribute in the structure, behavior, physiology or genome of an organism and are the fundamental data of systematics. The basic research strategy of systematics is to map the distribution of characters among taxa (species, genera, etc.), and use concordant patterns of character occurrence to formulate hypotheses about phylogeny. Character data are now presented in computer-manipulable form as taxon by character matrices with a number in each cell. These matrices may be very large, since it is now recognized that, in order to formulate robust phylogenetic hypotheses, systematists must deal with large data sets. I am presently, again in collaboration with John Bolt, constructing a novel method for the dissemination and use of this kind of information. In a data structure entitled PRESERVE, we are providing a web-based work site for all the morphological characters that have been used in systematic work on Paleozoic tetrapods and their antecedent sarcopterygian fishes along with useful supporting data. This site will also provide for the synthetic use of this character data and the formulation of novel characters. Scientists and their students from around the world will be able to carry on collaborative systematic studies at the site. This is a large project involving a world-wide editorial board of expert paleontologists. Programming work is now in progress on a second, upgraded version of the data structure and web interface.

Selected Publications

Sumida, S. S., R. E. Lombard, D. S Berman, and A. C. Henrici. 1998. Late Paleozoic Amniotes and their near relatives from Utah and Northeastern Arizona, with comments on the Permian—Pennsylvanian in Utah and Northern Arizona. In: Vertebrate Paleontology in Utah. B. Collette, Ed. Utah Geological Survey. Pp 21-30.

Sumida, S. S., J. B. D. Walliser, and R. E. Lombard. 1998. Late Paleozoic amphibian-grade tetrapods of Utah. In: Vertebrate Paleontology in Utah. Utah Geological Survey. B. Collette, Ed. Pp 31-44.

Lombard, R., E., and J. R. Bolt. 1999. A microsaur from the Mississippian of Illinois and a standard format for morphological characters. Journal of Paleontology, 73 (5): 908-923.

Bolt, J. R. and R. E. Lombard. 1999. Paleobiology of Whatcheeria deltae, a Mississippian primitive amphibian. In: Amphibian Biology, Vol. 4, Paleobiology. H. Heatwole, Edt. Surrey Beatty & Sons. Pp. 1044-1052.

Bolt, J. R. and R. E. Lombard. 2001. The mandible of the primitive tetrapod Greererpeton, and the early evolution of the tetrapod lower jaw. Journal of Paleontology, 75 (5): 1016-1042.

Lombard, R. E., and J. R. Bolt. 2006. The mandible of Whatcheeria deltae, an early tetrapod from the Late Mississippian of Iowa. In: Carrano, M. T. et al., eds., Amniote Paleobiology: Perspectives on the Evolution of Mammals, Birds, and Reptiles. University of Chicago Press, pp. 21-52.

Bolt, J. R., and R. E. Lombard. 2006. Sigournea multidentata, a new stem tetrapod from the Upper Mississippian of Iowa, USA. Journal of Paleontology 80: 717-725.

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