The Potapaco sands of the Nanjemoy Formation in Virginia yield a rich Ypresian fauna. Despite serious research in the past, a great deal of less studied opinion has crept into the faunal make-up of these sediments. By creating this page and ascribing names for the former owners of these teeth, we to are tendering opinions.

Some identifications are straight forward, unanimous opinions across the board - however many are subject to interpretation and evaluation. An attempt will be made for those species to point out differing opinions when known. Please feel free to contact us with alternate opinions or to point out errors.

The Nanjemoy Formation (Early Eocene - Ypresian) is made up of two members, the Potapaco and Woodstock. The below faunal list is currently skewed by the extensive collecting of Bed "B" of the Potapaco member. Over time, data from other levels and locales should help bring this page into balance.

The clayey sands and fauna of the primary collecting locale suggest a near shore (100-200m) marine environment. This fauna is rich in vertebrate fossils -- producing material from fishes, reptiles, birds and occasionally, land mammals. Besides abundant chondrichthyan teeth, this is one of the few locations where sea snake vertebrae may be deemed common.

CHONDRICHTHYAN FAUNA

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HEXANCHIFORMES
Hexanchidae GRAY, 1851
Specimen Required		Notorynchus serratissimus (AGASSIZ, 1843) - Sevengill shark. Reported by Kent (1994) as rare in Nanjemoy sediments.
		Hexanchus cf collinsonae WARD, 1979 - Sixgill shark. Uncommon in the Nanjemoy, these teeth were originally thought to represent H. agassizi CAPPETTA, 1976.
SQUALIFORMES
Echinorhinidae GILL, 1862
		Echinorhinus priscus ARAMBOURG 1952 - Bramble shark. Scarce in Nanjemoy sediments.
Squalidae BONAPARTE 1834
		Squalus crenatidens ARAMBOURG 1952 - Dogfish shark. Scarce in Nanjemoy sediments.
		"Megasqualus" orpiensis WINKLER, 1874 - Extinct dogfish shark genus. An uncommon but easily recognized tooth. Kent (in: Weems, et al, 1999) ascribes these teeth to Squalus crenatidens (ARAMBOURG, 1952). Cappetta has questioned the validity of the genus Megasqualus.
		Isistius trituratus (WINKLER, 1874) - Cookiecutter shark. The small fragile teeth of this species are relatively uncommon in Nanjemoy sediments.
SQUATINIFORMES
Squatinidae BONAPARTE, 1838
		Squatina "prima" (WINKLER, 1874) - Angel shark. Teeth of this design are relatively common in Potapaco sediments.
HETERODONTIFORMES
Heterodontidae GRAY, 1851
		Heterodontus sp - Bullhead shark. Scarce in studied Potapaco sediments, more common in other locales. Ward & Wiest (1990) and Kent (in: Weems, et al, 1999) attribute H. cf lerichei to the Potapaco.
		Heterodontus sp - Bullhead shark. Scarce in studied Potapaco sediments, these teeth appear to be quite distinct from the H. lerichei tooth design.
ORECTOLOBIFORMES
Ginglymostomatidae GILL 1862
		Delpitoscyllium africanum (LERICHE 1927) - Extinct nurse shark. (Formerly placed in Ginglymostoma.) Uncommon in the Potapaco (Bed "B"), this species is usually associated with Paleocene sediments.
		Ginglymostoma khouribgaense NOUBHANI & CAPPETTA, 1997 - Nurse shark. Illustrated specimen from basal Nanjemoy (Potapaco Bed "A") sediments.
		Ginglymostoma maroccanum NOUBHANI & CAPPETTA, 1997. - Nurse shark. Teeth of this design are scarce in Nanjemoy sediments. Kent (in: Weems, et al, 1999) attributes teeth of this design to G. subafricanum LERICHE, 1927. see: Ward (pers com).
		Ginglymostoma sp undescribed - Nurse shark. A common odontological design in certain Potapaco sediments, these teeth are often ascribed to G. serra, a Miocene species. see: Ward (pers com).
		Nebrius obliquus (LEIDY, 1877) - Nurse shark. Scarce in Nanjemoy, teeth of this design have previously been attributed to N. blanckenhorni (STROMER, 1905) & N. thielensis (WINKLER, 1873) see: Ward (pers com).
Rhiniodontidae MÜLLER & HENLE 1839
		Palaeorhincodon daouii NOUBHANI & CAPPETTA, 1997 - Extinct whale shark. These teeth are beautiful, quite distinct and less common than those of P. dartevellei.
		Palaeorhincodon dartevellei (ARAMBOURG, 1952) - Extinct whale shark. A scarce to rare Nanjemoy species.
LAMNIFORMES
In 2005, Cappetta and Nolf released Revision de quelques Odontaspidae (Neoselachii: Lamniformes) du Paleocene et de l'Eocene du Bassin de la mer du Nord. The impact of this paper greatly effects the naming of many of the North American taxa as well. In order to judge it's relevancy and allow others to evaulate their determinations, elasmo.com provides a review of this paper.
Cretoxyrhinidae GLIKMAN 1958
		Cretalamna appendiculata (AGASSIZ 1843) - Extinct mackerel shark genus. Teeth from this genus are somewhat common in the Potapaco member of the Nanjemoy Formation.
Jaekelotodontidae GLIKMAN 1964
		Jaekelotodus robustus (LERICHE, 1921) - Exinct lamniform genus. Teeth of this design are uncommon in Potapaco sediments and were previously attributed to Carcharias.
Lamnidae MÜLLER & HENLE 1838
		Isurolamna inflata (LERICHE, 1905) - Extinct mackerel shark genus. Uncommon in Nanjemoy sediments. This tooth-design was originally included as I. affinis (CASIER, 1946), see genus page.
		Serratolamna cf gafsana - Extinct lamniform genus. Uncommon in Nanjemoy sediments. Teeth of this design have previously been referred to as S. cf aschersoni (STROMER, 1905).
		Xiphodolamia ensis LEIDY, 1877 - Extinct mackerel shark genus. Teeth from this deep-water genus are uncommon, and have only been found in Potapaco Bed "C" and the Woodstock members of the Nanjemoy Formation.
Mitsukurinidae JORDAN 1898
		Anomotodon cf novus (WINKLER 1874) - Extinct goblin shark genus. Teeth from this species are common in the Nanjemoy.
		Anomotodon cf sheppyensis (CASIER 1966) - Extinct goblin shark genus. Teeth of this design were first recognized as a distinct species by Cunningham and Ward. They appear to be somewhat common in the Nanjemoy of Potapaco Bed B.
Odontaspididae MÜLLER & HENLE 1839
* * Odontaspis Affinity * *
		Odontaspis winkleri LERICHE, 1905 - Smalltooth sand tiger. A common species in Nanjemoy sediments.
		cf Palaeohypotodus rutoti ( WINKELR, 1874) - Extinct odontaspid genus. There are differing opinions on the identification of these teeth. One school of thought considers them to be Palaeohypotodus rutoti, others say definitely not (see Kent in: Weems, et al, 1999). Uncommon in Nanjemoy sediments.
* * Carcharias Affinity * *
		Brachycarcharias lerichei (CASIER, 1946) - Extinct sand tiger-like genus. Abundant in Nanjemoy sediments. Depending on author, previously attributed to Carcharias, Lamna, Cretalamna or Serratolamna.
		Carcharias sp - Extant sand tiger-like genus. Teeth comparing well with the Carcharias tooth-design are present in the fauna..
		Hypotodus verticalis (AGASSIZ, 1843) - Extinct sand tiger genus. A relatively common tooth-design in certain Nanjemoy sediments. These teeth had been previously assigned to Carcharias hopei
		Striatolamia macrota (AGASSIZ, 1843) - Extinct sand tiger- like genus. Abundant in Nanjemoy sediments.
		Striatolamia striata (WINKLER, 1874) - Extinct sand tiger- like genus. These teeth are common, but could possibly represent juvenile S. macrota
		Sylvestrilamia cf teretidens (WHITE, 1931) - Extinct sand tiger genus. Teeth from this tooth-design are common in the Nanjemoy and were formerly ascribed to Carcharias.
Otodontidae GLIKMAN 1964
		Otodus obliquus AGASSIZ, 1843 - Extinct mackerel shark genus. Relatively uncommon in both Potapaco sediments and those from the lower Woodstock. The authors are no longer convinced that the C. appendiculata-like teeth represent Otodus juveniles.
		Carcharocles aksuaticus (MENNER, 1928) - Extinct megatoothed mackerel shark. Uncommon in the Woodstock member of Nanjemoy. These teeth had previously been ascribed on this page to O. subserratus.
		Carcharocles auriculatus (BLAINVILLE, 1818) - Extinct megatoothed shark. Uncommon in Nanjemoy sediments and limited to the upper Woodstock Member. Adjoining image from the Nanjemoy of Maryland.
CARCHARINIFORMES
Scyliorhinidae GILL, 1862
		Scyliorhinus cf entomodon NOUBHANI & CAPPETTA, 1977 - Catshark. Relatively common in certain Potapaco (Bed "B") sediments.
		Premontreia cf degremonti CAPPETTA, 1992 - Extinct catshark genus Relatively common in certain Potapaco (Bed "B") sediments.
		Premontreia cf subulidens (ARAMBOURG, 1952) - Extinct catshark genus Uncommon in Potapaco (Bed "B") sediments..
Triakidae GRAY, 1851
		Triakis sp - Houndshark. Somewhat uncommon in Nanjemoy sediments, teeth of this design were originally included as Scyliorhinus. Cappetta and Noubhani both suggested Triakis undetermined for these teeth.
		Pachygaleus lefevrei (DAIMERIES, 1891) - Extinct houndshark genus. Formerly ascribed to Galeorhinus, teeth of this species are common in Potapaco sediments.
		Galeorhinus aff ypresiensis CASIER, 1946 - Tope Shark Common in Nanjemoy sediments.
Carcharhinidae JORDAN & EVERMANN, 1896
		Abdounia beaugei (ARAMBOURG, 1935) - Extinct requiem shark genus. Abundant in Nanjemoy sediments.
		Abdounia undesc - Extinct requiem shark genus. Common in Potapaco Bed "B" sediments.
		Abdounia recticona (WINKLER, 1873) - Extinct requiem shark genus. Not found by the authors in Potapaco Bed A & B sediments of Stafford Co. VA, this species has been collected in Woodstock member deposits. Kent (in: Weems, et al, 1999) reports this species from Potapaco Bed B.
		Galeocerdo latidens (AGASSIZ, 1843) - Tiger shark As is the case with A. recticona, this species has been found in the Woodstock member of the Nanjemoy.
		Physogaleus ?secundus (WINKLER, 1874) - Extinct ground shark genus. Abundant in Nanjemoy sediments. Specimens of the P. tertius tooth-design also present.
		Rhizoprionodon sp - Sharpnose shark Uncommon to scarce in Nanjemoy sediments.
PRISTIFORMES
Pristidae BONAPARTE 1838
		Pristis cf lathami GALEOTTI, 1837 - Sawfish. Uncommon in Nanjemoy sediments, larger rostral teeth of this species are quite distinctive. In addition to adult teeth, neonate teeth are found in Potapaco Bed B sediments.
		Anoxypristis sp - Sawfish. Uncommon in Nanjemoy sediments, this rostral tooth variation likely equates with Kent's (1999) A. mucrodens (WHITE 1926)
RAJIFORMES
Rhinobatidae MÜLLER & HENLE 1838
		Rhinobatos sp - Guitarfish. Relatively uncommon in Nanjemoy (Potapaco Beds A & B) sediments. Ward & Wiest (1990) reported R. bruxelliensis (JAEKEL, 1894) from the Woodstock.
Rajidae BLAINVILLE 1816
		"Raja" sp - Skate. A scarce genus in Nanjemoy sediments, illustrated example from Potapaco Bed "A".
MYLIOBATIFORMES
Uncertain
		Meridiania convexa CASE 1994 - Extinct ray genus. Scarce and usually well worn in Potapaco Bed B sediments.
		Uncertain species. Illustrated Potapaco Bed "A" specimen is uncommon in Nanjemoy sediments. We thought this tooth might represent Eotorpedo, but it was identified by one paleontologist as Heterotorpedo and by another as Jacquhermania.
Dasyatidae JORDAN 1888 or dasyatid-like
		Hypolophodon cf sylvestris - Extinct stingray genus. Somewhat common in certain Potapaco sediments.
		"Dasyatis" sp - Stingray. Only three of these have been reported, so must be deemed quite scarce in Potapaco Bed B sediments.
		Coupatezia woutersi (WINKLER, 1874) - Extinct stingray genus Abundant in certain Potapaco sediments. Ward & Wiest (1990) reported this species from the Potapaco & Woodstock members.
		Jacquhermania cf duponti (WINKLER, 1874) - Extinct stingray genus Relatively common in certain Potapaco sediments.
		? Jacquhermania duponti Uncommon in Potapaco sediments, this tooth-design is reminiscent of extant gymnurids (Butterfly rays). This likely represents Jacquhermania.
		Heterobatis-like - Extinct ray genus Common in Potapaco Bed 'B' sediments. Though these teeth appear very similar to the Moroccan Heterobatis teeth, these may represent a diffferent genus.
Myliobatidae BONAPARTE, 1838
		"Myliobatis" latidens WOODWARD, 1888 - Eagle ray genus Isolated teeth from this species are the most abundant myliobatid material in Nanjemoy sediments.
		"Myliobatis" toliapicus AGASSIZ, 1843 - Eagle ray genus Teeth from this species are common in Nanjemoy's Potapaco Bed B.
		"Myliobatis" dixoni AGASSIZ, 1843 - Eagle ray genus Present but less common than the above myliobatids in Potapaco Bed B.
		Uncertain myliobatid - Eagle ray genus Uncommon in Nanjemoy sediments, this design was referred to by Kent (1999) as Aetomylaeus. The authors' are not comfortable with this identification.
		Pseudaetobatus sp CAPPETTA, 1986 - Eagle ray genus Teeth of this design are uncommon to scarce in Potapaco Bed B. and are referred to by Kent (1999) as Aetobatus.
		Aetobatus irregularis (AGASSIZ, 1843) - Eagle ray genus Present in the Nanjemoy, the earliest specimens noted by the authors are from Potapaco Bed C sediments. Kent (1999) reported species from Potapaco Bed B.
		Undescribed myliobatoid - Eagle ray genus. Known from isolated teeth only (rare), they were originally thought to be "M." nzadinrnsis-like in design. However, based on diagnostic characteristics, it is difficult to determine if these teeth should be placed with the myliobatids or rhinopterids.
Rhinopteridae JORDAN & EVERMANN 1896
		Rhinopterid sp "A" - Cow-nose ray genus Common in Nanjemoy sediments.
		?Rhinopterid sp "B" - Cow-nose ray genus Common in Nanjemoy sediments.
		Rhinopterid sp "C" - Cow-nose ray genus Common in Nanjemoy sediments.
Mobulidae GILL 1893
		Burnhamia sp - Extinct devil ray genus Abundant in Potapaco sediments. Similar to B. fetahi CAPPETTA 1985.
		Eomobula cf stehmanni HERMAN et al., 1989 - Extinct ray genus A single anterior is known by the authors from Nanjemoy sediments (Potapaco, Bed "B"). A myliobatoid lateral, sometimes recovered from these sediments, is thought to also represent Eomobula.
		Archaeomanta melenhorsti HERMAN, 1979 - Extinct devil ray genus. Very common in Potapaco 'B' sediments.
		cf Mobula sp - Devil ray. Singular specimen known to authors from Nanjemoy sediments (Potapaco, Bed "A"). Specimen should be deemed a possible contaminent unless additional specimen(s) recovered.