“Endemism” Relative to Space, Time, and Taxonomic Level

Lawrence J Flynn,Michèle E Morgan,David Pilbeam,John C Barry

doi:10.5735/086.051.0223

Lawrence J Flynn, Michèle E Morgan + Show 2 more

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https://doi.org/10.5735/086.051.0223

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Abstract

Faunal assemblages consist of immigrants, endemics and long-term residents; changes in proportions of these categories through time reflect general aspects of faunal stability and turnover. To study stability and change in the long biostratigraphic succession of Miocene terrestrial mammalian faunas recorded mainly in the Potwar Plateau Siwaliks of Pakistan, we distinguish long-term residents and assess new appearances as endemic vs. immigrant components. Our data represent the biogeography of the northern Indian subcontinent, but because neighboring areas of similar age are not as well known, virtually all species are found only there, and the proportion of the fauna that is immigrant is not apparent. We use preceding faunal assemblages to judge whether individual species might have originated there. We find many long-term residents in the Siwaliks, and of new species, most are immigrants and fewer are likely to have originated endemically. Siwalik rodents and artiodactyls show high rates of immigration f...

Highlights

We are the beneficiaries of almost two hundred years of research on the terrestrial fossil record of the Siwalik deposits of the Indian subcontinent
In addition to smaller samples elsewhere, modern research collections reside in Islamabad, at both the Geological Survey of Pakistan and the Pakistan Museum of Natural History, and presently in the Department of Human Evolutionary Biology, Harvard University, Cambridge, Massachusetts
Other than “X” for 22 Ma occurrences, each species is judged for its first record as either an immigrant (I) or an endemic (E); later repeated presences are noted as residents (R)

Summary

Introduction

We are the beneficiaries of almost two hundred years of research on the terrestrial fossil record of the Siwalik deposits of the Indian subcontinent. Explorers began to amass what became extensive collections of fossil vertebrates at the Geological Survey of India, Calcutta; the Natural History Museum, London; the American Museum of Natural History, New York; and the Peabody Museum of Natural History, New Haven, Connecticut. In addition to smaller samples elsewhere, modern research collections reside in Islamabad, at both the Geological Survey of Pakistan and the Pakistan Museum of Natural History, and presently in the Department of Human Evolutionary Biology, Harvard University, Cambridge, Massachusetts. It is the combined information held in and flowing from these collections that allows us to pose ever more sophisticated questions in evolutionary paleobiology.

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