Nurse sharks have a long fossil history. Compagno (1999) includes as extant members of this family: Ginglymostoma cirratum (BONNATERRE, 1788), Pseudoginglymostoma brevicaudatum (GÜNTHER, 1866) and Nebrius ferrugineus (LESSON 1830).

G. cirratum is the most widely distributed genus (tropical and warm temperate waters of the Atlantic and eastern Pacific) and the only known from North American waters. P. brevicaudatum is a common, bottom dwelling inshore (to 12 meters) shark. Active at night, it feeds on invertebrates (crustaceans, cephalopods, echinoderms and mollusks) also fish and stingrays. These sharks often school, and can reach three meters in length.

Illustrations in Compagno show the living Ginglymostoma teeth as having a relatively high central cusp with two lateral cusplets, and Nebrius, a relatively low central cusp with multiple lateral cusplets.

The grasping dentition of these sharks can be said to have monognathic heterodonty, in that upper and lower teeth are relatively similar. Positional differences are generally limited to crowns becoming lower distally and more symmetrical, medially. Discussing fossil teeth, Cappetta (1987: 79-80) noted that the teeth can reach 1.2 cm in width and have up to 10 cusplets.

In general, viewed labially the crown has a triangular appearance, with the central cusp becoming less prominent as the number of cusplets increase. A broad, sometimes bifid, apron overhangs the root. The labial crown face may, or may not, be ornamented with enameloid ridges. The lingual face extends out over a strong protuberance of the root. Viewed basally, the root lobes are splayed creating a "V" appearance. A foramen extends from the lingual face of the protuberance to the nutrient groove. The groove also bears a central pore, which opens into the expanding groove. The marginal root face bears one or more pairs of foramina.

CRETACEOUS

Much has happened to the five Cretaceous species noted in Cappetta (1987), see: Noubhani & Cappetta (1997):

  • G. globidens CAPPETTA & CASE 1975 [Mt Laurel Sands, Upper Campanian, New Jersey] is suspected to be Plicatoscyllium,
  • G. lehneri LERICHE 1938 has been synonymized with Plicatoscyllium minutum,
  • G. lithuanica DALINKEVICUS 1935 was determined to be Heterodontus and not an orectolobid,
  • G. minutum (FORIR, 1887) has been reassigned to Plicatoscyllium, and
  • G. rugosum DARTEVELLE & CASIER 1943 was synonymized with Plicatoscyllium minutum. (SEE: Plicatoscyllium).
    Noubhani & Cappetta (1997) added three new of species to the Cretaceous of Morocco: G. botmaense [Maastrichtian], G. erramii [Late Maastrichtian] and G. pectinatum [Late Maastrichtian].

    Case & Cappetta (1997:136 pl 6. fig 4) reported a single damaged specimen from the Maastrichtian of Texas but hesitated to attribute it to a particular species. Hartstein, Decina & Keil (1999:21, Pl. 2, Fig 18, 19, 21) depicted three teeth form the Severn Fm. (Maastrichtian, MD) they ascribed to Ginglymostoma sp. Hamm & Cicimurri (2011:113) included Ginglymostoma sp in the Atco Formation (Early Coniacian) of Texas.

    ?Ginglymostoma globidens. Kent (1994: 32-35) includes this species in the late Cretaceous faunas of New Jersey, Delaware and the Chesapeake. He points out that these teeth have a relatively stout crown with one or two lateral cusplets and weak labial ornamentation. Schwimmer (1986: 114) reported this species from the Campanian of Georgia. In 1999, this website included G. globidens in the NC Campanian fauna.

    ?Ginglymostoma botmaense. Recent (2007) finds of nurse shark teeth in reworked Late Cretaceous material in Wayne Co., NC suggests a second taxon (in addition to G. globidens) is present . Certain smaller specimens have smooth labial faces, well defined cusplets and generally compare with G. botmaense; unfortunately, the roots are too damaged to attribute them to this species at this time (see: undetermined species C). There was a single non-plicated specimen with good lobes from this site; however, its overall similarity with Plicatoscyllium minutum led me to incorporate it on that page.

    PALEOGENE

    Four Paleogene species were included by Cappetta (1987):

  • G. angolense DARTEVELLE & CASIER 1943 [Ypresian, Eocene western Africa & West Indies],
  • G. serra (LEIDY, 1877) [Eocene Maryland],
  • G. sokotoense WHITE 1934 [Thanetian, Palaeocene Niger] and
  • G. subafricanum ARAMBOURG 1952 [Danian, Palaeocene Morocco]. Noubhani and Cappetta (1997) described three new Moroccan species: G. chenanei [Thanetian Palaeocene], G. khouribgaense [Danian, Thanetian Palaeocene] and G. maroccanum [Ypresian Eocene].
    NOTE: G. africanum LERICHE 1927 has been moved to the new genus     Delpitoscyllium NOUBAHANI & CAPPETTA (1997).

    Müller (1999:34) reported G. delfortriei DAIMERIES 1889 from the Belgrade Fm (Oligocene) of NC. Images of these specimens (Pl.2, Fig. 2-4) include a large number of cusplets on each shoulder and appear more likely to represent Nebrius.

    Ginglymostoma subafricanum. The Aquia produces teeth that conform well with those ascribed to this species. Ward & Weist (1990) had previously included G. subafricanum in the Brightseat Frm (Danian) of Maryland. Kent (in: Weems, et al, 1999) included G. subafricanum in the Nanjemoy fauna, but these were later shown to be G. maroccanum (see below).

    Ginglymostoma maroccanum. The Nanjemoy (Potapaco, Bed "B") produces teeth that conform well with those ascribed to this species. Kent (in: Weems, et al, 1999) included these teeth in the Nanjemoy fauna as G. subafricanum. Kent (1994) had previously included G. subafricanum in the Chesapeake fauna, noting that they were similar to G. africanum but with a relatively slender cusp and sloping lateral margins. Case (1994) included G. subafricanum in the Late Palaeocene - Early Eocene fauna of Mississippi. See Ward (pers comm) comments on this identification.

    Ginglymostoma sp undescribed. Although commonly referred to as G. serra, that species was described based on teeth from Miocene sediments of North Carolina [see Ward (pers comm) comments]. Kent (in: Weems, et al, 1999) identified these teeth as G. serra and (in Kent 1994) notes that teeth from this species are known from Eocene of Maryland and the middle-late Eocene of Albania. He describes them as similar to G. lehneri (= Plicatoscyllium minutum) but with multiple cusplets.

    Ginglymostoma khouribgaense. Bed "A" of the Nanjemoy Formation (Ypresian) has produced a tooth that conforms very well with the description and illustrations of this species. View a SEM of this tooth courtesy of Fred Cassel.

    NEOGENE

    Cappetta (1987) includes two extinct species, G. delfortriei DAIMERIES 1889 from the Miocene of Europe and Africa and G. malembeense DARTEVELLE & CASIER 1943 from Miocene of West Africa.

    Ginglymostoma sp. Tailings from the mine in Aurora rarely yield a Nurse shark teeth. Those specimens seen by the author have all been from DPW material, thought to be of Pungo River Fm (Lower Miocene) origin. Most of these teeth have root damage, which would question the validity of any identification. However, the accompanying illustration is clearly a nurse shark. The author is of the opinion that these teeth likely represent the extant species G. cirratum

    Selected References

    Cappetta, H., 1987. Chondrichthyes II. Mesozoic and Cenozoic Elasmobranchii. In: Handbook of Paleoichthyologie, vol. 3b, Gustav Fischer Verleg, Stuttgart, 193 pp.
    Cappetta, H. & Case, G., 1975. Contribution à l'étude des sélaciens du groupe Monmouth (Campanien - Maestrichtian) du New Jersey. Palaeontographica Abteilung A, 151:1-46.
    Case, G., 1994. Fossil Fish Remains fron the Late Paleocene Tuscahoma and Early Eocene Bashi Formations of Meridian, Lauderdale County, Mississippi. Palaeontographica Abt. A, 230, pp 97-138.
    Case, G. R., and H. Cappetta. 1997. A new selachian fauna from the late Maastrichtian of Texas. Muünchener Geowissenschaften Abhandungen 34:131-189.
    Compagno, L.J., 1999. Checklist of living elasmobranchs. In Sharks, skates, and Rays - The Biology of Elasmobranch Fishes. Hamlett, W. C. ed. John Hopkins University Press, Baltimore MD, USA. pp 471-498.
    Hamm, S.A. and D.J. Cicimurri, 2011. Early Coniacian (Late Cretaceous) selachian fauna from the basal Atco Formation, Lower Austin Group, north central Texas; Paludicola [Rochester Institute of Vertebrate Paleontology] 8(3):107-127.
    Hartstein, E., Decina, L. and Keil, R., 1999. A Late Cretaceous (Severn Formation) Vertebrate Assemblage from Bowie, Maryland. The Mosasaur, 6:17-23.
    Kent, B., 1994. Fossil Sharks of the Chesapeake Region. Egan Rees & Boyer, Maryland. 146 pp
    Kent, B. 1999. Sharks from the Fisher/Sullivan Site. In: Weems, R. & Grimsley, G., Early Eocene Vertebrates and Plants from the Fisher/Sullivan Site (Nanjemoy Formation) Stafford County, Virginia. Virginia Division of Mineral Resources, Pub 152: 11-37.
    Leriche, M., 1942. Contribution à l'étude des faunes ichthyologiques marines des terrains Tertiaires de la Plaine Côtière Atlantique et du centre des Etats Unis. Mémoire de la Société Géologique de France, Paris, new series, 43:1-111.
    Müller, A. 1999. Ichthyofaunen aus dem atlantischen Tertiär der USA. Leipziger Geowissenschafteb, Leipzig, 9/10: 1-360.
    Noubhani, A and Cappetta, H., 1997. Les Orectolobiformes, Carcharhiniformes et Myliobatiformes des Bassins à phosphate du Moroc (Maastrichtien-Lutétien basal)., PalaeoIchthyologica 8, München. 327 pp
    Schwimmer, D., 1986. Late Cretaceous fossils from the Blufftown Formation (Campanian) in western Georgia. The Mosasaur, III:109-119.
    Ward, D. and Wiest, R., 1990. A checklist of Paleocene and Eocene sharks and rays (Chondrichthyes) from the Pamunkey Group, Maryland and Virginia, USA. Tertiary Res., 12(2) p 81-88.
    Welton, B. and Farish, R., 1993. The Collector's Guide to Fossil Sharks and Rays from the Cretaceous of Texas. Before Time, Texas. 204 pp.

     

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