The purpose of this communication is to report on the vertebrate remains, excluding peshcoliths, collected so far. Wheeler of the University of North Carolina allowed publication on specimens not previously reported in the literature. The ages of the five post-Yorktown, pre-Recent formations are still imprecisely known.
On the basis of the small amount of weathering shown in the post-Yorktown formations, Oaks (1964, p. The base of the Sand layer is mixed with fine sand and silt and is unfossiliferous at the western end of the pit.
A worm pipe reef occurs in the upper two to four feet of most of the pit. Bird and mammal remains occur mainly in the lower six inches of the fossiliferous gravel layer, which also contains an abundance of coarse shell detritus. Some of the bones in the canal, including long, slender bird bones, were found unbroken in a vertical position, suggesting rapid deposition.
Many bones that occur outside the boundaries of the channel have been found along the bottom plane between the marine sand and beach sand layers.
ANNOTATED LIST
8 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL, 153 referred to by Oaks (1964, p. 137) as a possible flow channel which Oaks (1964, p. 137) refers to as a possible flow channel developed in the top of the Norfolk Formation, possibly during a brief post-Norfolk, pre-Kempsville emerging episode. Oaks (1968, pers. comm.) now believes that a marine origin is more likely, possibly as a 'tidal channel along the base of the beach wall, or as a tidal channel just landward of a small emerging beach ridge.' One of us (Drez ) recently observed that the worm tube layer, which occurs only in the top few meters of the Norfolk Formation, is. Currently in the western Atlantic Ocean they appear to be coastal forms, distributed from the Gulf of Maine to the east coast of Florida.
In summer, the greatest concentration of the number of individuals is observed in the area between Cape Cod and DelawareBay. The largest populations of living forms are in the tropical and semitropical zones of the earth. In the Western Atlantic, several well-established species of Carcharhinus combine habits of incursion into coastal, littoral environments with northward migration during warm times.
The collection includes a single curved spine (USNM 25080) as it occurs in pectoral fin batteries of the skate. Material evidence for the geological history of skates is limited, although well-preserved specimens of Cyclohatis from Lebanon show the existence of the family in the Upper Cretaceous. A number of species of skate are normal inhabitants of Virginia's coastal waters at this time.
A tail stinger (USNM 25073) and a pavement tooth (USNM 25074) are assigned to the genus Dasyatis.
10 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 1 53 barbel probably is derived from the Norfolk Formation, and the
The final distribution in the waters of the Western Atlantic continental shelf is from Massachusetts to Texas. One humerus, obviously an adult, has the side of the head broken, but is otherwise quite complete. The outline and curvature of the axis are identical to that of the adult, as it is.
The third humerus, missing most of the head, is of adult size and quite worn. While this is the first report of the gannet from the Pleistocene of North America, its remains have been reported from deposits of this era in Norway and Denmark. The Thebrant, common in Virginia in the historic period up to the end of the 19th century, is now a regular migrant, but in smaller numbers than formerly.
Large-scale persecution of its nesting sites, it was reduced in number at the beginning of the 18th century. Greatauk bones have been found in prehistoric archaeological deposits along the Atlantic coast of the United States in Massachusetts and Florida. North America, and is also the first definite report of the species for the state of Virginia.
It is known elsewhere in North America from the late Pleistocene on the coast of California and in Western Europe from Ireland, England, Norway, Denmark and Gibraltar. An incomplete lumbar vertebra from facies 8 of the Norfolk Formation and a single pectoral element from the fossiliferous gravel layer of the Kempsville Formation, both in the Womack borrow pit, belong to some species but have not been further identified. The walrus is represented by only one specimen of known provenance: a baculum lacking both extremities (USNM 24864) collected from the fossiliferous gravel bed of the Kempsville Forma-.
A second specimen that may have originally come from one of the local borrow pits is an incomplete left maxilla with three-sided teeth. Although a single southern fossil record for the sea can be explained as a vagrant (with difficulty given the impossibility. It may also be suggested that the sea was a regular member of the fauna off southeastern Virginia during Kempsville time, although more speci- .
The combined result of eversion, central thinning and support is the formation of a deep fossa on the lateral surface of the ilium. A few Pleistocene records far south of the present range, such as those based on the tentatively identified innominate bone from Edisto Island, remain rightly suspect as possibly exceptional events.
20 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 1 53
DISCUSSION
Very little is actually known about the role of climatic factors in the distribution of large vertebrates. Applying this procedure only to the Atlantic sea bream in the western North Atlantic would indicate that it is strictly an Arctic species (Loughrey, 1959, Map 1). The sea naturally thrives at high latitudes, and climate, especially temperature, is clearly a potential limiting factor in (seasonal) dispersal (Fay and Ray, 1968; Ray and Fay, 1968), and was probably the critical factor before the rise of Man.
However, the modern distribution of walruses undoubtedly represents only that fraction of their former range least visited by their most powerful enemy, Man. The widespread occurrence of gray seals in recent centers of southern New England, compared to their current marginal occurrence off Nantucket, where a few survive possibly through recolonization with waning human vested interest in their destruction and the resulting increasing population pressure from the north , indicates that they have found suitable habitat within Recent times in places where they do not occur now. The possible limiting influence of man, including Paleoindians, on the distribution limits of suitable prey species (walrus, gray seal, gannet), which are highly vulnerable at critical periods in the reproductive cycle, must be considered in the attempt to explain this.
Oaks (1967, personal communication) suggested another possible factor contributing to the northward retreat of island-nesting vertebrates as follows: "Possible destruction of favorable coastal nesting sites by stabilization of sea level and subsequent wave action of unconsolidated sediments offshore." could be as important a factor as human actions." He suggests further. 153(1968, personal communication) that by stabilizing lagoon filling (1968, personal communication) that by stabilizing lagoon filling behind barrier islands, terrestrial predators might give easier access to these breeding sites that were previously well offshore. These could certainly be factors in the local retreat of the species from a particular nesting site such as Kempsville Island (Fig. 1, inset), but islands are still abundant along much of the northeast coast.
The fossil fishes are potentially useful paleoclimatic indicators in view of their relative independence from the activities of man. at least in the past) and from details of coastal geomorphology. Unfortunately, great breadth of distribution (partly seasonal) and the general impracticability of specific identification combine to produce returns. The fishes represent a large segment of the recent marine and brackish water fauna of Chesapeake Bay and the Virginia coast.
The available fossil sample is insufficient to determine the dominance of southern or northern populations, but to our present knowledge there is no discernible difference in temperature. In summary, the evidence is conflicting and inconclusive regarding the interpretation of southern records for northern vertebrates in the Kempsville Formation, although a paleoclimatic explanation seems the most convincing from a biological perspective. Further work on radiometric dating and stratigraphy of the area and study of additional vertebrate and invertebrate fossils.
LITERATURE CITED
Determinación de la edad, madurez sexual, longevidad y esperanza de vida en la foca gris {Halichoerus grypiis). Foca de la especie Halichoerus grypiis (Fabricius), anillada en la isla de Ransey (Gales) y capturada en Santoña (provincia de Santander).
