Event Description
Nate Shoobs, PhD Candidate,
Department of Biodiversity, Earth and Environmental Science, Drexel
University
Biodiversity,
Evolution, and Extinction in the Imperiled Galápagos-Endemic Land Snail Genus Naesiotus
Though virtually unknown to the public in comparison to their charismatic
vertebrate neighbors, such as Darwin's finches or giant tortoises, the
bulimulid land snails of the genus Naesiotus (Gastropoda: Stylommatophora:
Bulimulidae) form the most species-rich and phenotypically diverse evolutionary
radiation endemic to the Galápagos archipelago.
The magnitude and evolutionary importance of Galápagos bulimulid diversity has
largely been veiled by a lack of basic taxonomic work on the group. While the
majority of species have been described for over a century, no comprehensive
systematic account of the Galápagos bulimulids has ever been completed, despite
numerous historical attempts. With 89 available names, 61 validly described
species and 10-20 new species in need of description, Naesiotus is long overdue
for a systematic revision , especially considering the unique importance of
this group for our understanding of the evolutionary dynamics of insular
evolutionary radiations.
The necessity of this work is compounded by the fact that, like many other
Pacific island land snail faunas, a significant number of Naesiotus species
have recently been driven extinct. Most species in the genus have suffered
dramatic reductions in population and range sizes since the mid 1970s. Insufficient
taxonomic knowledge of both the past and present diversity and distributions of
Naesiotus species precludes an actionable understanding of their evolution or
their rapid, ongoing extinction.
In this talk, we provide an overview of what is known about the diversity,
distribution, and rapid decline of this spectacular, yet poorly known portion
of the Galápagos terrestrial fauna drawing from phylogenetic and morphological
studies, extensive field surveys, and the examination of all extant museum material.
Next
Seminar: October 3rd, 2019, Jason P. Downs, PhD, Delaware
Valley University, ANSP Research Associate
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