
3/10/10 – The Hodson Collection
Here’s a very nicely preserved ark clam named
Arca (Scapharca) mirandana H. K. Hodson (in F. Hodson, H. K. Hodson & Harris), 1927. Your first question is probably “why the extra long name?” That is largely due to mixed authorship – a practice that is a little awkward but is still done today. More about this below.
The publication: In the 1927 paper written by Floyd Hodson, Helen Hodson, and Gilbert Harris (
Bulletins of American Paleontology no. 49, “Some Venezuelan and Caribbean Mollusks”), the authors apparently split up the duties. Some of the new species in this paper are authored by Floyd Hodson; others are authored by Helen Hodson or the two of them together. I do not see any species authored by Gilbert Harris, who was probably an advisor on the project [he was Floyd’s graduate advisor at Cornell University in the 1920s]. The paper is an unusual one in another aspect – it includes many, many species descriptions, most of them new, but absolutely no discussion or description of the locality. [This would be pretty much unacceptable today.] The very brief introduction to the paper reads “The collections upon which this article is based were made in Venezuela for an American company. Only descriptions of species with general localities and general ages can be given at present, but later, when the interests of the company permit, we hope to publish definite localities and stratigraphic ranges for the species.” These were collections made for an oil company. As was mentioned last week, oil companies once employed paleontologists and relied upon fossils to identify likely places to drill for oil. Thus their locations were somewhat secretive in some cases, which seemed to be the case here. I do not know whether more precise localities were ever published; the specimen label here still is very imprecise: Oligocene-Miocene, locality no. 6, District of Miranda, State of Zulia, Venezuela.
The specimen: This is the holotype* specimen of
Arca mirandana, and is 25 millimeters (approximately 1 inch) long. There are about 250 living species of the family Arcidae worldwide today, distributed mainly in intertidal or shallow waters. They attach to rocks using strong, elastic
byssal threads secreted by the foot. Some species are exploited for human food in Asia, and have been raised in aquaculture in China and Japan since the seventeenth century.
The collection: PRI is now curating more of the Hodson Collection (only the type specimens had been cataloged previously), which includes bulk lots from approximately 2,000 localities plus the original catalogs (which presumably do contain more precise locality information). Much of this collection is Pliocene to Recent mollusks and has been described by our collections staff as a “goldmine.” Curation of the Hodson Collection is supported by a National Science Foundation grant that also allowed us to install compactor shelving for our fossil mollusk collection. Fossil mollusks of Cenozoic age are one of the great strengths of the PRI Research Collections.
*See
Fossil of the Week 8/19/09 - Cerithium gainesensis for a definition of "holotype."
Text by Paula Mikkelsen