Maryland Department of Natural Resources


Miocene fossils of Maryland

1957, Vokes, H.E. (1st Edition)

2000, Vokes, H.E., Glaser, J.D., and Conkwright, R.D. (2nd Edition)

Bulletin 20


In 1685 Martin Lister, a famous European scientist, published a work on mollusca in which he illustrated a fossil shell, now known as Ecphora quadricostata (Say) (Pl. 25, fig. 1). This was the first American fossil figured in a scientific work. The original specimen came from the Miocene deposits of Maryland, probably from the vicinity of St. Marys City where it is relatively common. From this early beginning the Miocene deposits of Maryland and their rich faunas of fossil shells have attracted much attention from scientific and non-scientific students and collectors. Interest has greatly increased during recent years with the development of the Chesapeake Bay area as a summer home region for residents of Baltimore and Washington and with the establishment of summer camps along its shores by the Boy and Girl Scouts of America, the Young Mens' Christian Association, and others.

The scientific study of the Maryland faunas was begun by Thomas Say in 1824 when he described a number of new species from collections made in the area by Professor John Finch of England. The most prolific student was, however, Timothy Abbott Conrad who began publishing descriptions of Maryland fossils in 1830 and continued to do so until 1869. Others who were interested in the faunas included Isaac and Henry Lea, William Wagner, and William Healey Dall. I heir studies were published in short papers in various scientific journals. There was no comprehensive study available to the nonscientific collector until 1904, when the Maryland Geological Survey published a large work consisting of a volume of text and a volume of illustrations describing and illustrating all of the known fossils from the Maryland Miocene. This work, which became the "bible" of collectors in the area is now out of print and unavailable except in scientific libraries. There has been an increasing demand for a guide to the faunas that will be available for, and intelligible to, non-scientific students and amateur collectors. This abbreviated discussion is designed to meet this demand.

This report does not include all of the species known to occur in Maryland Miocene faunas. It does include illustrations of all of the common species of the larger fossils and at least one representative of the genera that occur less abundantly. Groups whose fossil remains are of microscopic size, or whose study and identification requires microscopic techniques, are not included.

The species are referred to by their scientific names. These consist of a minimum of three words: the first is the name of the genus or group to which the species belongs, the second is the name of the species, and the third is the name of the man who first recognized the species as constituting a distinctive unit and who described it scientifically. When the name of the author of the species is enclosed in parentheses it means that at the time that he described the species he referred it to a genus different from that to which it is now referred. Thus, in the case of Macrocallisla marylandica (Conrad) (Pl. 16, fig. 1, 2), the species was originally described by Conrad as Cylherea marylandica, but the species marylandica is no longer considered as being referable to the genus Cylherea, so that Conrad's name is placed in parentheses. The generic and the specific names are always printed in a different type-face from that of the author as well as of that of the main body of the text

A number of the generic names here used differ from those used in the Maryland Geological Survey's Miocene report. Those here used represent the consensus of present opinion as to the correct names to be applied to the species concerned. While some may mourn the demise of familiar names, this discussion is designed for students and beginners in the field of fossil study, and it seems most desirable that they begin at the level of our present knowledge.