Shark Fossils
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Figs. 1a, 1b. Odontaspis cuspidata (Agassiz). | ||
| 1a) Outer face of a tooth showing a rudimentary
second pair of lateral denticles. St. Mary's River.
1b) Inner face of the same specimen. |
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| Fig. 2a, 2b, 3. Odontaspis elegans (Agassiz). | |||
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2a) Outer face of a small tooth. Plum Point. 2b)Inner face of the same specimen. 3). Outer face of a somewhat worn tooth, the lateral denticles broken away. |
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| Fig. 4. Oxyrhina desorii Agassiz. | |||
| 4) Inner face of a moderate-sized tooth. Charles County near the Patuxent River. Acad. Nat. Sci., Phila. | |||
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Figs, 5a-6c. Oxyrhina hastalis Agassiz. |
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5a) Inner face of a medium-sized and somewhat worn specimen. Flag Pond. 5b) Outer face of the same specimen. 6a). Outer face of a large-sized lateral tooth. Jones Wharf. 6b). Profile of the same specimen. 6c) Inner face of the same specimen. |
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| Fig. 7. Oxyrhina sillimani Gibbes. | |||
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7) Outer face of an average-sized tooth. Fairhaven. |
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| Figs. 8, 9. Otodus obliquus Agassiz. | |||
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8) Inner face of a small-sized specimen with erect crown. Charles County near the Patuxent River. Acad. Nat. Sci., Phila. 9) Inner face of a small-sized lateral tooth with oblique crown. Charles County near the Patuxent River. Acad. Nat. Sci., Phila. |
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Suborder ASTEROSPONDYLI.
Family LAMNIDAE Müller and Henle.
Genus Odontaspis Agassiz.
Odontaspis cuspidata (Agassiz).
Lamna cuspidata Agassiz, 1843, Poiss. Foss., vol. iii, p. 290, pl. xxxvii a, figs. 43-50.
Odontaspis cuspidata Eastman, 1901, Md. Geol. Survey, Eocene, p. 105, pl. xiv, figs.
la, Ib, 6a, 6b.
Lamna cuspidata Hay, 1902, Bull. 179, U.S. Geol. Survey, p. 302.
This species occurs with rather less frequency
in the Miocene than in the Eocene of this state, and is found principally at
Plum Point and Fairhaven. All the examples observed are of the anterior dentition,
and in the majority of cases are more or less water-worn.
Occurrence.—Calvert formation. Charles
County near the Patuxent river,
Plum Point, Fairhaven.
Collections.—Maryland Geological Survey,
Johns Hopkins University, Philadelphia Academy
of Natural Sciences, Museum of Comparative Zoology.
Lamna elegans Agassiz, 1843, Poiss. Foss., vol. iii, p. 369, pl. xl. b, fig. 24, (non pl.
xxxv, figs. 1-7, nec pl. xxxvii a, figs. 58-59).
Odontaspis elegant Eastman, 1901, Md. Geol. Survey, Eocene, p. 104, pl. xvi, figs.
2a, 2b, 2c, 3a, 3b, 3c.
Lamna elegans Hay, 1902, Bull. 179, U.S. Geol. Survey, p. 308.
Notwithstanding this is the most abundant of
all sharks' teeth in the Eocene of Maryland and adjoining states, it is extremely
uncommon in the Miocene. It is recorded by Cope from the Miocene of Charles
County in this state, and from Cumberland County, New Jersey, but no examples
are preserved in the Museum of the Philadelphia Academy of Natural Sciences
with the rest of the Thomas Collection, which formed the basis of Cope's report.
The dozen or so of specimens obtained by the Survey are all from Plum Point,
and were found commingled with teeth of the preceding species.
Occurrence.— Calvert formation. Plum
Point.
Collection.— Maryland Geological Survey.
This genus is distinguished from Lamna by the prevailing absence of lateral denticles in the teeth, and as shown by several nearly complete skeletons from the Upper Cretaceous of this country and Italy, has remained practically constant from Mesozoic time to the present.
Oxyrhina desorii Agassiz, 1843, Poiss. Foss., vol. iii., p. 282, pl. xxxvii, figs. 8-13.
Oxyrhina desorii Gibbes, 1847, Proc. Acad. Nat. Sci. Phila., vol. iii, p. 267.
Oxyrhina desorii Gibbes, 1849, Jour. Acad. Nat. Sci. Phila., 2nd ser., vol. i, p. 203,
pl. xxvii, figs. 169-171.
Oxyrhina wilsoni Gibbes, 1849, Jour. Acad. Nat. Sci. Phila., 2nd ser., vol. i, p. 203,
pl. xxvii, figs. 172, 178.
Oxyrhina desorii Emmons, 1858, Rept. N. Car. Geol. Survey, p. 236, fig. 67.
Oxyrhina desorii Woodward, 1889, Rept. N. Cat. Fos. Fishes, Brit. Mus., pt.1, p.383.
Isurus desorii Hay, 1902, Bull. 179, U.S. Geol. Survey, p. 305.
Description.— "Anterior teeth
narrow, much elevated, and robust; crown much curved inwards, the outer coronal
face nearly flat, the inner very convex; root with two elongated branches diverging
at an acute angle. Lateral teeth more compressed, with a shorter root having
more divergent branches; crown narrow, the cutting-edges in most cases gradually
diverging to the extremities of the base, and the apex rarely reflexed."
— Woodward.
The original of Plate XXX, Fig.
4, is an average-sized specimen of the anterior series of teeth; it belongs
to the Museum of the Philadelphia Academy of Natural Sciences.
Occurrence.— Calvert formation. Plum
Point, Charles County near the Patuxent river.
Collections.— Maryland Geological
Survey, Philadelphia Academy of
Natural Sciences, Museum of Comparative Zoology.
Oxyrhina hastalis Agassiz, 1843, Poiss. Foss., vol. iii, p. 277, pl. xxxiv, (excl. figs.
1, 2, ? 14).
Oxyrhina hastalis Eastman, 1895, Palaeontogr., vol. xli, p. 178 (complete literature
references and syonymy).
Oxyrhina hastalis Clark, 1895, Johns Hopkins Univ. Circ., vol. xv, p. 4.
Oxyrhina hastlalis Clark, 1896, Bull. 141, U.S. Geol. Survey, p. 42.
Oxyrhina hastlalis Woodward, 1889, Rept. N. Cat. Fos. Fishes, Brit. Mus., pt.1, p.386.
Isurus hastalis Hay, 1902, Bull. 179, U.S. Geol. Survey, p. 306.
Description.— "Teeth attaining
a large size, broad, thin, compressed; outer coronal face flat or concave, rarely
with vertical wrinkles; root short, the branches very divergent, usually blunt
and abbreviated. Anterior teeth large, triangular and relatively broad, the
crown only gently curved outwards at the apex; coronal edges of the lateral
teeth gradually curving to the extremities of the base, the apex often bent
slightly outwards."—Woodward.
The teeth of this species are rather more abundant
than those of O. desorii, which accompany it at Plum Point and in Charles
County. The example figured is from the former locality, and is one of the largest
lateral teeth in the collection, its total height being very nearly 6 cm.
Occurrence.— Choptank formation. Jones
Wharf, Flag Pond. Calvert formation.
Plum Point, Fairhaven, Charles County near the Patuxent river.
Collections.— Maryland Geological
Survey, Johns Hopkins University, Philadelphia
Academy of Natural Sciences, Museum of Comparative Zoology.
Oxyrhina sillimani Gibbes, 1847, Proc. Acad. Nat. Sci. Phila., vol. iii, p. 268.
Oxyrhina sillimani Gibbes, 1849, Jour. Acad. Nat. Sci. Phila., 2nd ser., vol. i, p.
202, pl. xxvii, figs. 166-168.
Isurus sillimani Hay, 1902, Bull. 179, U.S. Geol. Survey, p. 307.
Description.—Teeth attaining a total
height of about 3 cm., and exhibiting much uniformity. Distinguished from O.
hastalis by the greater thickness of the crown, which is slightly convex
on its outer surface, and by having a deeper and more expanded root with divergent
branches. Coronal apex sometimes curved backwards, but never bent out of the
vertical plane.
This species occurs in about equal frequency with
O. desorii, which it accompanies. The example figured is one of the lateral
teeth and shows the characteristic form of the root which serves to distinguish
this species from O. hastalis.
Occurrence.—Calvert formation. Plum
Point, Fairhaven. Charles County near the Patuxent river.
Collections.—Maryland Geological Survey,
Philadelphia Academy of Natural
Sciences, Museum of Comparative Zoology.
Oxyrhina minuta Agassiz, 1843, Poiss. Foss., vol. iii, p. 385, pl. xxxvi, figs. 36-39.
Oxyrhina minuta Gibbes, 1849, Jour. Acad. Nat. Sci. Phila., 2nd ser., vol. i, p. 202,
pl. xxvii, figs. 161-163 (non fig. 164).
Isurus minutus Hay, 1902, Bull. 179, U.S. Geol. Survey, p. 306.
It is doubtful if the imperfect teeth from the Eocene of South Carolina assigned to this species by Gibbes properly belong here, and it is practically certain that the species is wrongly recorded by Cope as occurring in the Miocene of Maryland and New Jersey. The specimens so determined by him appear to be young examples of O. sillimani and O. desorii, together with some that are clearly referable to Carcharias.
Genus Otodus Agassiz.
Otodus obliquus Agassiz.
Otodus obliquus Agassiz, 1843, Poiss. Foss., vol. iii, p. 267, pl. xxxi, pl. xxxvi, figs.
22-27.
Otodus obliquus Eastman, 1901, Md. Geol. Survey, Eocene, p. 106, pl. xv.
This species, so abundant in the Eocene, occurs
very sparingly in the Miocene of this State, the few examples known having been
obtained from Charles County, and forming part of the Thomas Collection.
Occurrence.— Calvert formation. Charles
County near the Patuxent river.
Collection.— Philadelphia Academy
of Natural Sciences.
updated 3/2/05
(these web pages were prepared by R. D. Conkwright)