ELASMO.COM Fossil Genera: Carcharhinus

In modern oceans, the gray sharks are a circumglobal genus largely inhabiting warm temperate to tropical waters. The thirty-one commonly recognized species span a range of: adult sizes (<1m - >3m), waters (inshore, offshore, reefs & freshwater rivers), prey (inverts, fish, turtles & mammals), dentition design (gradational, usually dignathic and weak sexual heterodonty) and functionality (clutching to cutting, usually a combination). During the 1980's, the genus as we view it today was reorganized/consolidated by Garrick, Compagno and others. These authors provided excellent descriptions over various papers; however, dentition-design was largely limited to tooth formulas, functionality and labial perspective tooth illustrations. Naylor & Marcus (1994) demonstrated the validity of relying on gradational heterodonty but were unable to reliably identify these teeth based solely on tooth outline (single perspective data collection).

During the 20th century, while ichthyologists were attempting to better refine specific definitions, paleontologists seemed (in my opinion) to go in the other direction -- lump teeth into the oldest possible buckets; ever-expanding the possible variations that might be attributed to one of those poorly defined archaic taxa. In the early 90s, I came under the influence of people such as Bob Purdy and Bill Heim who were advocating that when dealing with Mio-Pliocene teeth, one should look first to Recent taxa (a logic I quickly embraced, not only for requiem and lamniform sharks but for batoids as well).

Dentition/Tooth-design

In modern gray sharks, a generalized description might be:

gradational dignathic heterodonty with cutting-clutching functionality;

15 tooth-positions(+/- 3 or 4) per quadrate in which the uppers are broader and more distally inclined than the lower. Lower tooth counts tend to be less than uppers;

one or more reduced teeth on or along the symphysis;

the upper teeth are usually fully serrate while lowers tend to have finer serrations and may be limited to portions of the main cusp;

the distal shoulder tends to have larger serrations (cusplets when highly enlarged) than the mesial;

compound serrations (serrations on serrations) are commonly present on large serrations/cusplets;

the nutrient groove is often well developed with a distinct foramen;

lower teeth tend to have thicker roots and have more lingually directed cusps than the corresponding upper;

sexual dimorphism is usually present and crown width, root thickness and/or lateral profile of the tooth;

individual variations appear to be represented by broad and narrow forms (regional variations appear to also be present).

Fossil Gray Sharks

God bless anyone who wants to figure out this mess. I intended to quickly summarize the fossil record by referencing Cappetta (1987:121-22) and then move on. Based on that book, the earliest occurrences of the genus appeared to be Stromer's (1905) report of Carcharias cf egertoni (AGASSIZ, 1843) from the ?Middle Eocene of Egypt, or gibbesi (WOODWARD, 1889) from the Middle Eocene of SE North America.

Egertoni, a trek through the published record

Aggasiz's (1843) Corax egertoni (Tertiary, Maryland; Vol 3, Plate 36 Fig 6 & 7, see fig. below) illustrations each appeared very similar with the modern C. leucus tooth-design (Agassiz's figure 6 is compared with the 7th and 9th file of a Recent 2.3m individual. Agassiz's two specimens provide a general design-envelope (triangular crown with a fully but evenly serrate cutting edge). This general tooth-design would become a paleo-bucket during the late-19th, early-20th centuries.
In this same volume(s) another paleo-bucket was erected, Sphyrna prisca (p234, Plate XXVI, Figs, 35-50); more than one species appears to be present in this group of generally well-damaged specimens (the better examples are represented in figure below).

Dames (1883) included from the Eocene of Egypt Corax egertoni and figured a single specimen (Fig 5, see fig. above) with a near complete serrate mesial edge and incomplete (probably damaged) distal; unlike the Agassiz specimens there is a low, elongated distal shoulder. Dames (pp 143-144, Tbl III, fig 7.a-p) went on to erect from the fauna Carcharias (Aprionodon) frequens for a Carcharhinus-like tooth-design (smooth cusp, serrate shoulders; see figs. - below).

Stromer (1905) published on the Eocene of Egypt and discussed ^A additional references to "egertoni"; adding to the list:

Woodward (1889) who attributed Gibbes (1849:19, pl 35, fig.66-68) teeth to Prionodon egertoni.

Priem (1897) included poorly illustrated specimens from Egypt as Prionodon.
Discussing "egertoni" (pg 177) he noted:

"The presence of a pulpage cavity and a distinct vertical furrow at the root gives favor to the .
"From Agassiz's tooth types they all differ in having a more regular convexity of the mesial cutting edge and the sharp flat angle at the distal edge..."
"In smaller teeth the crown is slightly slender and a bit more bent backward, so they resemble teeth of Galeocerdo very much..." however, "..."In Galeocerdo, the serration of the teeth is stronger beneath the notch."
"Teeth pictured by Alessandri (1895) from the Neogene of Piedmont (Italy) of Prionodon egertoni resemble my specimens perfectly well,..."
"The upper teeth of a recent jaw of Prionodon aff falciformis BIBRON I have in front of me and of Prionodon menisorah Val. after Mueller & Henle (1841) ^B are bent exactly the same way. In Galeocerdo, the serration of the teeth is stronger beneath the notch."

In the end, Stromer settled on Carcharias (Prionodon) cf egertoni for his teeth (pl XVI, fig 17-19, see fig. below), which don't compare well the Agassiz or Dames specimens. Fig 17 is somewhat close to Eastman's and might possibly represent an Eocene representative of the perezii (POEY, 1876) lineage; this particular specimen is very similar to a "Negaprion" gibbesi tooth illustrated in White (1956:143, fig. 79) from the Eocene of Alabama. Stromer also included an additional tooth-design as Carcharias (Prionodon) sp nov. sp. (Fig 16, see fig. below.)

Case & Cappetta (1990) is another of the sometimes baffling papers that document this fauna. They dropped "egertoni" entirely when reporting on the Fayum depression of Egypt and included:

Carcharhinus frequens (pg 12; pl. 5, figs. 102-07; pl, 7, figs. 143-48 & 151-59) was used for a tooth-design that in my opinion is not present in Dames (1905) although these authors included those specimens in their description. They defined the dentition as dignathic with broader uppers. a non-serrate cutting edge and that, "the cutting edges of the heals bear irregular and very obtuse indentations". Not only do these specimens not belong in frequens, but it appears possible two (or more) taxa are included in their suite of images. In the Late Eocene of Western Sahara, what appear to be similar tooth-designs are present. The narrower form (i.e., C&C figs. 5.106-07 & 7.157-59) are represented by both upper and lower variations (fig. below) and the 'undulated shoulder' form (C&C 5.102-105) with comparatively robust examples (fig below). In the case of the latter ('undulated shoulder'), it is uncertain to this author what the nature and form of the associated lowers might be. The dentition could be dignathic with subtle differences between quadrates or monognathic -- therefore, these two tooth-designs are included herein as carcharhinid sp 1 and 2 only.

Carcharhinus sp 1 (pg 12; pl.7, figs. 164, 165) as described and figured was very similar to Dames' (1883 pl 3, fig 5) Corax egertoni and the examples provided above (figs. & ). However, they made no mention of the Dames' specimen but did synonymzed Stromer's (1905, pl. 16, figs. 17, 18) Carcharias cf egertoni.

Carcharhinus sp 2 (pg 13; pl.5, figs. 100, 101; pl. 8, figs. 176-177) are noted as having serrate shoulders and smooth cusps. In my opinion these correspond with Dames' (1883 pl 3, fig 7) Carcharias frequens specimens (see above).

Eocene take-away

The above cursory look at a single comment by Cappetta (1987: 121) clearly illustrates the complexity of this issue; I have no intention of trying to resolve this or many other problems with the determinations in the published record. There appear to be a number of apparently valid Carcharhinus Eocene species, but egertoni is not one of them:

C. frequens (Dames 1883) Late Eocene, Fayum Depression, Egypt

C. nigeriensis (White 1926) Eocene, Nigeria

C. marçaisi (Arambourg 1952) Lower Middle Eocene, Ganntour Basin Morocco

C. sp 1 Case & Cappetta 1990 ?Late Eocene, Fayum Depression, Egypt
and likely others. Depending on author:

Woodward's (1889) Carcharias (Aprionodon) gibbesii (Mid Eocene, US) is referred to as Carcharhinus, Sphyrna or Negaprion.

White's 1926 Aprionodon amekiensis (Mid Eocene, Nigeria) could be Negaprion (Cappetta 1987: 124) or Carcharhinus.
Time and further research will likely remove some of the discussed tooth-designs from Carcharhinus and attribute them to other genera (i.e., Abdounia, Galeocerdo, Negaprion and/or others); however, the net effect is likely not to erase Carcharhinus from the Middle-Late Eocene fossil record of northern Africa.

Neogene determinations are far worse than their Paleogene counterparts; however, it is well beyond the expertise of this author to competently address the issues surrounding these taxa or the paleo-buckets employed for Neogene teeth in general. The following section includes at this time only gray shark-like teeth recovered along the east coast of North America.

Fossil Record -- Western North Atlantic

Home of those problematic egertoni teeth, the record is no less confusing in North America where authors continued to follow Agassiz's lead; the determining characteristic initially appeared to have been serrate and 'large vs small'.

Traditional nomenclature

Gibbes (1849) included from the "Eocene" (which included Oligocene at the time and probably inadvertent Miocene) of South Carolina (see figures and below):

p192, pl XXV.66-69 Galeocerdo egertoni (AGASSIZ 1843); noted he'd also seen them from the Calvert Formation;

p194, pl XXV.86,87 Glyphis subulata GIBBES 1847; and

p194, pl XXV.88-90 Sphyrna prisca AGASSIZ 1843)
The G. egertoni specimens (particularly 66 & 69) have the appearance of a C. leucus upper and the G. subulata figure 86 could very well represent a C. leucus lower anterior.

Emmons (1858: 240-42) included a number of "Eocene" tooth-designs from North Carolina (which might have been lumped into the "prisca"-bucket at that time): Lamna compressa (Figs, 79-81) and Otodus (Figs, 83a & 85a).
In addition, the paper included as a Carcharodon (Fig. 90; per Manning, an errata sheet noted it as Galeocerdo egertoni) a tooth that fails to appear Eocene in origin.

Cope (1867: 141-142) reported as Yorktown epoch but said not to be Pliocene, specimens from Charles Co. MD near the Patuxent River (Miocene). The specimens were not illustrated but appear to have been used in part by Eastman (1904, see below). He included:

Galeocerdo egertoni, likely Carcharhinus perezii.

Galeocerdo laevissimus nov. sp. reported as a common design totally lacking serrations with a short basal cutting edge. These teeth likely represent the extant Sphyrna zygaena.

Sphyrna prisca, likely Carcharhinus brachyurus (GÜNTHER, 1870).

Sphyrna magna nov sp was described as shoulder elongated, crenate and separated from the cusp by a notch. "Crown is slightly to markedly oblique, rather narrow and stout, slightly bent outwards, with a sharp and entirely smooth cutting edges. Both faces convex the outer much more so, the inner with a slight groove at the base."

Woodward, (1889: 437) erected Carcharias (Aprionodon) gibbesii for 3 small teeth which Gibbes (1849, figs 63-65) had attributed to Galeocerdo minor (Eocene of Europe); Woodward deemed these "Eocene" of South Carolina specimens represented a distinct taxon.

Eastman (1901). In his Eocene of Maryland paper, the author reported (see figure below):

Sphyrna prisca (p 110, Pl XIV, Figs. 7) as abundant in the Eocene of SC and Miocene of MD; in doing so, he included Emmons (1858) Figs. 79-81 and 84a. Interestingly, he noted "only two or three rather imperfect examples have been obtained from the Eocene of this state" (MD). The illustrated example (Fig. 7) was reported from the Aquia Formation at Liverpool Point, MD -- a Palaeocene site.

Galeocerdo latidens AGASSIZ 1843 (p 109, Pl XIV, Figs. 8) from the Woodstock Fm (Ypresian, MD). He noted that the design is not uncommon in the Miocene, but only one example had been recovered from the Eocene (don't ask me.) In the Eocene, this tooth-design is generally deemed Physogaleus "secundus" by collectors today; however, Leriche 1942 would discuss this tooth, therefore it has been included.

Hay (1902) attempted to straighten-out this taxonomic quagmire; he included under and ascribed to Carcharhinus (pp 312-313):

C. (Prionace) antiquus (AGASSIZ 1856) — Miocene, CA

C. (Prionace) egertoni (AGASSIZ 1843): — Eocene SC; Miocene MD & NC.
Many of Cope's Galeocerdo; Emmons (1858 fig 90, Galeocerdo); Gibbes Glyphis subulata & Galeocerdo egertoni (1849, figs 66-69); and Woodward's Carcharias (Prionodon ).

C. (Aprionodon) gibbesii (WOODWARD 1889) — Eocene SC, AL; Miocene MD.
Woodward's Carcharias (Aprionodon); Cope (1867) Oxyrhina minuta AGASSIZ 1843; Eastman (1895: 182) Carcharias; Gibbes (1846: 42) Galeocerdo minor, (1849: 63-65) G. minor & (1849: 164) Oxyrhina minuta; and Leidy (1877: 254) Prionodon antiquus.

C. (Prionace) tenuis (AGASSIZ 1843 XXXa, fig 15) Carcharias — Senonian, Switzerland; Eocene?, SC.
Gibbes (1849a: 191) Carcharias; Gibbes (1850: 300, pl XLII fig 8) Carcharias; and Woodward (1889: 442) Carcharias (Prionodon)
(311)

Galeocerdo laevissimus COPE 1867:141 Miocene of MD
(314)

Sphyrna gibbesii Emmons 1858b:241 (additions & corrections) S. denticulata; and Gibbes 1849:196, pl XXV, fig.94 S. denticulata

Sphyrna magna Cope 1867:142 & Woodward 1889:455; Miocene, MD.

Sphyrna prisca AG 1843, XXVIa, fig 35-50 — Miocene Europe, MD, NJ, NC, SC; Cope (1867: 142, 1875h:362, 1875v:29) Zygena; Gibbes (1889a: 194 pl XXV.88-90); and Woodward (1889d: 453).

Eastman (1904) disregarded Hay's suggestions and reported from the Miocene of Maryland (see figs. below):

Carcharias (Prionodon) egertoni (p 84, pl XXXII, fig.1) and depicted a tooth which better compares with a similarly aged Carcharhinus perezii tooth from Lee Creek than with C. leucus. He describes them as, "upper teeth broad, triangular, prominently serrated, both margins slightly concave. Lower teeth probably narrower than the upper, robust and prominently serrated" and notes them as present in the Calvert Fm. (MD).

Carcharias laevissimus (p 84-85, pl XXXII, fig.2); the author notes they are similar to egertoni but lack serrations. The figured specimen is from Cope's type specimens (Miocene, Charles Co, MD). The figured specimen compares well with the extant Sphyrna zygaena (LINNAEUS, 1758), a true hammerhead.

Carcharias collata sp. nov. (p 85, pl XXXII, fig.3-5) a named (Sphyrna collata) but unpublished Cope determination and noted, "coronal edges with extremely minute serrations disappearing toward the base". The illustrations, horizon (Choptank & Calvert) and description of these teeth suggest lowers of C. perezii; Leriche (1942:81) would subsequently synonymize C. collata with Prionodon egertoni.

Carcharias magna (p 86, pl XXXII, fig.6-7); Eastman notes that the teeth are relatively large (nearly 2 cm) with a sharp, non-serrate cutting edge on the cusp; slightly "crimped" on the shoulder. The root is short and "considerably thickened on the inner face." [This tooth-design is Negaprion-like.]

Sphyrna prisca (p 91, pl XXXII, fig 15) was reported and the author attributed S. denticulata of Emmons (p 241, fig 84a) to it. He described prisca as, "small, pointed and finely serrated" .. "met with quite frequently in Miocene " of Chesapeake region. "... very abundant in Eocene of SC, but the specimens figured under the names Gibbes [1849, pl XXV, Figs 88-90] have the appearance of belonging to Carcharias rather than Sphyrna. Only two or three teeth of this species have been obtained from the Eocene of Maryland. The Miocene specimens included by Eastman most likely represent the extant Carcharhinus brachyurus."

Fowler (1911) Reported on specimens from the upper Cretaceous or Miocene beds^C of New Jersey (stratigraphy and sometimes locales unknown).

Glyphis egertoni (pg 75, fig 36) was accompanied by numerous illustrations (Fig. above) but he confessed, "The specimens I have listed all appear to belong to this species, though the differences between Aprionodon gibbessi, Sphyrna prisca and Glyphis egertoni are scarcely evident in some cases. The latter may, to some extent, be characterized by its broad upper teeth." Multiple tooth-designs are represented in figure 36.

Sphyrna gibbesii (pg 78. fig 37) was noted to be small (8 mm) and agreed with Gibbes' Sphyrna denticulata; reported from ?upper Cretaceous Beds of Monmouth Co., NJ. (See fig. above.)

Sphyrna prisca (pg 78-79, fig 38) was also represented by numerous (Fig. above) figured specimens from the Miocene of MD. He noted that they were called Carcharias collata by Eastman and only known from the Miocene of Cumberland Co. (NJ) by Cope.^D In any event; he provided some disclaimer verbiage as he did with egertoni. Multiple species appear to be present in these figured specimens as well.
It is hard to glean relevant information from this paper other than the "wild west" nature that seemed to be present at the turn of the century (19-20th).

Leriche (1942) reported on Cenozoic sharks of the Western Atlantic. Relevant to this review are:

Prionodon egertoni (pp 80-82) reported from the Calvert & Yorktown Fms (Mio-Pliocene) of MD/VA/NC, Neogene (Ashley Phosphate beds) of SC & Hawthorne Fm. of FL. The author figured twenty-two specimens (pl VII, Figs. 1-22); 12 uppers (1-12) and 10 lowers (13-22) that appear to have represented more than one taxon. He discussed differences between these teeth and those of Prionodon lamia (RAFINESQUE, 1810)^E. Leriche added to the ever-growing egertoni bucket Cope / Eastman's Carcharias collata and Fowler's Glyphis egertoni teeth.

Prionodon carolinensis nov sp (pp 82-83) erected for the tooth included by Gibbes (1849: 192, pl. XXV, fig 66) as Galeocerdo egertoni from the "Eocene" of SC (a leucus-like design); no illustration was provided but he discussed the similarities and differences of these teeth with those of Prionodon amboinensis (MÜLLER & HENLE, 1839) (an extant taxon sometimes confused with C. leucus). This specimen was likely Neogene and probably C. leucus.

Prionodon? gibbesi (pg 83) was briefly mentioned but not figured; from the Chesapeake region and SC.

Sphyrna? americana nov sp (pg 86, pl. VI, figs 6-8) was erected for the tooth-design attributed to S. prisca by Gibbes (Pl. XXV, fig. 88-90). Leriche noted the cusp is narrow with a fully serrate cutting edge; fine on the cusp, somewhat stronger on the shoulders. The author considered attributing them to Prionodon but found the widening of the crown base too abrupt and the tooth more similar to Sphyrna magna. He attributed them to the Neogene (of the Ashley Phosphate Beds) near Charleston, SC. [Figures 6 & 7 could represent Negaprion eurybathrodon {BLAKE, 1862), Bill Heim thinks figure 8 might be C. perezii.]

Sphyrna prisca var eastmani nov. var. (pg 85, fig. 7, pl VII.28-32) erected for U.S. prisca-like teeth which somewhat differed from their European counterparts. Leriche's specimens were collect below the cliffs at Plum Pt. (Calvert Fm., Miocene, MD); and compare very well with those of similarly-aged Carcharhinus perezii from Lee Creek.

Sphyrna gilmorei nov sp (p 47, pl. IV, fig 1) was erected on the basis of a single tooth from the Eocene of Choctaw Co., AL. Leriche noted the tooth was compressed, the cutting edge smooth on the cusp and crenulated on the shoulders.

Sphyrna magna (p 85); Leriche noted the size, smooth main cusp and crenulated shoulders but compared it only with S. elongata LERICHE 1910 and the smaller S. prisca (not his new S. americana, although he referred to magna in that description).

Sphyrna sp (p 36); Leriche considered the two Paleogene teeth included by Eastman 1901 (see figure above) as from a single species. He noted that Eastman's S. prisca (fig. 7) differed from typical Miocene (?assume European) examples by its more irregular and less fine denticles on the heel.

White (1956) argued that Woodward's (1889) Alabama specimens (derived from various collections) were contaminated with Cretaceous & European material, and that Leriche (1942) had overlooked important specimens from the Eocene of Alabama; he proceeded to more fully document the state's Eocene faunas and to tender additional opinions.

Hypoprion greyegertoni nov sp (p 137-39; text figs 48-56, pl 11.7) was described as: Teeth up to 1.2 cm in height with sigmoidal profile; crown with a smooth narrow cusp and wide, shallow, faintly crenulated shoulders. Roots relatively massive, high, well separated with a deep nutrient groove. Upper teeth are slightly broader and more distally inclined than the lowers (upper anteriors had twisted crowns). Hypoprion at the time included macloti, hemiodon and signatus. [I find the association of these teeth and the determination that they belong in "Hypoprion" very suspect.] .

Negaprion gibbesi (139-43, fig 22,23,27,57-93, Pl 11, figs 9, 10). Based on Bigelow & Schroeder's (1948: 310, text fig. 52) illustrated tooth-set and tooth-design, White deemed these teeth should be attributed to Negaprion. He noted that Woodward (1889:439) merely relied on the Gibbes (1848) paper for a description (relatively robust & broad, coronal margin often feebly crimped) and provided no illustrations. White also thought that Woodward's gibbesi syntypes included specimens belonging to: Negaprion magnus, Sphyrna americana, Sphyrna laevissa, C. egertoni, Alopias latidens and Lamna verticalis.

Negaprion gibbesi var gilmorei nov var (p 142-44). White also recognized two variations of the design and proposed the finely "crimped" examples from SC be referred to as gibbesi ("typical form"; text figs 77-96, pl 11.9) and the AL ones to gibbesi var gilmorei (text figs 22,23,27,57-76, pl 11.10; Mid-Upr Eocene).

Case (1980) reported on the Trent Marls (Oligocene^F) of North Carolina. In this paper he included:

Negaprion gibbesi (pp 88-89, pl 5, figs 9-10) synonymizing teeth previously reported by prior authors as gibbesi or gibbesi gilmorei and the Recent Aprionodon acutidens queenslandicus WHITLEY 1939^G.

Carcharhinus priscus (p 89, pl 6, figs. 6-7) included a frighteningly long list (n=40) of synonyms (that ever enlarging bucket). Consider all the above citations of prisca/priscus and add for flavour: Carcharias (Aprionodon) stellatus & brevis PROBST 1878, Sphyrna elongata LERICHE 1910, Carcharias (Hypoprion) acanthodon LERICHE 1926, Aprionodon cf collata Leriche (1957), Carcharias (Prionodon) egertoni Case (1967), Alopecias exigua & Cestracion priscus of Menesini (1969)

Aprionodon acuarias (PROBST, 1879). Case (1980: 90, pl 6, figs 8,9) reported these as common small (4-8mm) teeth with slender smooth crowns, "becoming extinct in the Helevetian" and only known from the Neogene of France.

Cappetta (1987) in summarizing carcharhiniform genera, included (relevant to the above):

Isogomphodon GILL 1861. Cappetta (p 120-21) included, I. acuarius (fig 103.a,b,c) and I. frequens; using the Recent I. oxyrhynchus (MÜLLER & HENLE, 1839) from Western Atlantic as a quide (narrow crowns, lowers smooth-edged, uppers finely serrate shoulders). [The large V-shaped roots of modern I. acuarius teeth are unlike those of the fossil "acuarius" and this tooth-design might represent a modern taxon such as Carcharhinus brevipinna (MÜLLER & HENLE, 1839).^H

Carcharhinus BLAINVILLE 1816. Cappetta (p 121-22) included: egertoni, gibbesi and priscus (fig 103.d,e,f.; Miocene of France).

Negaprion WHITLEY 1940. Cappetta (p 124) mentioned only N. amekiensis and eurybathrodon (fig 105.b-e; Miocene, France)

Kent (1994: 80-82) reported seven Carcharhinus species from the Chesapeake region.
— Eocene —

C. gibbesi (fig. 11.4a) with a smooth cusp & serrate shoulders; Piney Point Fm.
— Miocene —

C. egertoni (figs. 11.4b,c) Calvert, Choptank & Eastover Fms.;

C. priscus (fig. 11.1d), noted the uppers & lowers were similar; Calvert, Choptank & Eastover Fms.;

C. cf macloti (MÜLLER & HENLE, 1839) (fig. 11.1e) from the lower Calvert;

Carcharhinus sp A (fig. 11.4f). Kent noted they were C. acronotus (POEY, 1860) -like, Calvert & Choptank Fms.; and

C.sp B (11.4g) - Calvert & Choptank Fms.
— Pliocene —

C. longimanus (POEY, 1861) (11.4 H), large teeth from the Yorktown Fm.
The clarity of the figures does not provide sufficient detail to properly comment on these determinations. Many of these taxa have been discussed previously; however, C. macloti is known from the Miocene of Lee Creek and appears valid. The most common large Carcharhinus tooth-design from the Pliocene at Lee Creek is C. obscurus (LESUEUR, 1818). As this species was not reported by Kent and Heim (pers com 2009) noted it was the most common in the Chesapeake's Yorktown, the C. longimanus attribution may be questionable.

Müller (1999) reported from the western North Atlantic:

Carcharhinus egertoni (pg 48, Pl 6, Figs 13-18) from the Calvert (MD) and Pungo River (NC) formations (Miocene). Figures 13-15 are C. perezii uppers in design; figs. 16-18 are lowers but are from one or more undetermined taxa.

C. elongatus (pg 48, Pl 6, figs. 5-9) from the Old Church (VA) and Ashley (SC) formations (Oligocene). Figures 7-9 are most likely an Oligocene variation (smooth-edged main cusp) of the C. falciformis lineage's uppers; figs. 5-6 are inconclusive.

C. gilmorei (pg 49, Pl 7, figs. 1) from the Piney Point Formation (Eocene) of Virginia; he synonymized with C. gilmorei: White's (1956) Negaprion gibbesi gilmorei and Hypoprion greyegertoni nov sp (in part; Upper Eocene of Alabama) and Case's (1981: 64, pl6, figs 1-3) Negaprion eurybathrodon. Müller's depicted specimen although Carcharhinus-like bears little similarity with Leriche's figured gilmorei specimen (pl IV, fig. 1).

C. priscus (pg 49; Pl 6, figs. 10-12) from the Calvert & Choptank (MD) and Belgrade & Pungo River (NC) formations. All these specimens compare well with extant C. brachyurus tooth-designs (10 possible lower, 11 male upper and 12 female upper).

Isogomphodon acuarias (PROBST, 1879) (pg 51, pl 7, fig. 9) From the Belgrade Fm. (Oligocene) of NC. The stated scale for this specimen was 1X, making it a very large carcharhinid tooth; it is assumed to be incorrect. Other than size, the depicted tooth-design appears to be that of a lower (?10th) from a male C. brachyurus.

Pterolamiops longimanus (pg 53; Pl 7, figs. 5-8, 12) from the Yorktown Formation (Pliocene, NC). The paper noted the image enlargement factor as 4.5x, probably a publishing error (more likely 1x). Most of these teeth represent positional variations of the extant C. obscurus; the angular mesial edge of figures 5a & b is a common ?pathology ^I in that taxon and figure 9 may be from C. leucus, but the damage is too extensive to be certain.

Included (pp 48-49) as Carcharhinus but not figured were: C. carolinensis ?Miocene, SC; C. signatus (POEY 1868) Pungo River, NC; and C. gibbesi.

At this point it becomes quite apparent that something is wrong — bucket-madness (lumpers gone wild).

Summary

The pre-2000 published determinations is (to be kind) somewhat questionable; it might be summarized as:

Egertoni. The usage of this specific name should probably be terminated; multiple tooth-designs have been placed into this bucket, but Agassiz's original figures strongly suggest that they represent the extant Bull Shark (Carcharhinus leucus).

Priscus. Through most of its published life in the US, this tooth-design was assigned to Sphyrna. In the late 20th century it was moved to Carcharhinus. Agassiz's illustrations for this tooth-design depict a thick crown, unlike the typical Carcharhinus tooth. The underlying species (priscus) may be valid in Europe, but the many US tooth-designs subsequently attributed to it are questionable (and in the US, the assignment to Carcharhinus likely incorrect).

Gibbesi. Sufficient reports appear to validate this general tooth-design as Eocene in origin. Leriche's gilmorei and White's general agreement strongly support the possibility of more than one variation during the Eocene. White's suggestion that these be attributed to Negaprion also appears to be a reasonable alternate theory. Until this matter can be better clarified, specimens might best be attributed to "N. gibbesi" to indicate the undifferentiated nature of these Eocene carcharhinid teeth.

Extant species. On several occasions, Neogene material was attributed to Recent taxa based on tooth-design and probably what had been reported previously. Relying on dentition-design and benefiting from hindsight, most of these determinations can be questioned.

Earliest record. Because there is an issue concerning the dating of "Ashley phosphate bed" material, the only good published example of early Paleogene specimens comes from Eastman (1901:110) when he wrote "only two or three rather imperfect examples have been obtained from the Eocene of this state" (Aquia Fm at Liverpool Pt, MD; Palaeocene); the poorly illustrated tooth (see figure above) and description ("Teeth small, broad, gently oblique, often erect, with finely serrated edges") could very well represent an early Carcharhinus. The accompanying image (Fig. ) represents what would also appear to represent this genus, it was recovered in situ from the Aquia's "zone 2".

A Fresh Approach. The publication of Purdy et al (2001) was a large step towards better understanding the gray sharks of the Western Atlantic. Traditional paleo-buckets were rejected, representational tooth-sets created and modern jaws used to identify the fossil reconstructions. Their research revealed a far more diverse fauna during both the Miocene and Pliocene than previously reported; and, called into questions the names traditionally applied to these teeth.

Lee Creek Fauna (Neogene Western North Atlantic)

Two distinct gray shark faunas are present at Lee Creek, warm water as reflected by Pungo River and a cooler by Yorktown Formations species. Many of the better-known taxa are sufficiently common to allow artificial upper tooth-set reconstructions; the less common rely on tooth-design (often dangerous considering the variability of individual teeth and the overlapping of positional designs between taxa). Few teeth can be found that are not represented by Recent species making it unnecessary to resort to using paleo-buckets. Purdy et al (2001) discussed this matter in detail; these pages are intended to build upon and more fully argue the rationale of looking to the present to better understand the past.

Chart comments: Entries, which include an image, indicate that a new or updated species page has been created or updated for this genus page. Those lacking an image are linked to the current Bill Heim pages; these will slowly be updated as well.
Confidence level relates to the strength of the arguments. This is directly related to the abundance of material, the ability to reconstruct an upper or lower file-set, the uniqueness of positional tooth-designs, the availability of comparative material and the ability to reproduce conclusions drawn by Bill Heim and/or Purdy et al (2001). (Low confidence means that only a minimal number of positional examples, which conform to Recent examples, are available.)


PUNGO RIVER FM. (Miocene) The warm waters of the Miocene were home to sharks and rays that are no longer reported from the today's North Carolina waters; many of the smaller gray sharks are now found along the Indian and western Pacific Oceans. Reported and unreported species include (updated species pages are notated by a linked image):
	C. brachyurus (GÜNTHER, 1870) -- Copper shark Abundant in Pungo River Confidence: Very high \| Upper reconstruction conforms with Recent tooth-set Extant: Circumglobal, subtropical Purdy et al (2001): Pungo units 1-5.
	C. falciformis (BIBRON, 1839) -- Silky shark Common in Pungo River Confidence: Very high \| Upper reconstruction conforms with Recent tooth-set Extant: Circumglobal, temperate / subtropical Purdy et al (2001): Pungo units 2-4.
	C. cf isodon (VALENCIENNES, 1839) -- Finetooth shark Scarce in Lower Pungo River tailings Confidence: high \| upper reconstruction conforms with Recent tooth-set. lowers cloaked by C. macloti. Extant: Gulf of Mexico Purdy et al (2001) do not include this tooth-design.
	*C. leucas* (VALENCIENNES, 1839) -- Bull shark Uncommon in the Yorktown, (smaller & less common in the PR). Confidence: medium-high \| Awaits tooth-set reconstruction Extant: Circumglobal, subtropical Purdy et al (2001) rare in PR units 1-5, common in YT units 1-3.
	*C. cf limbatus* (VALENCIENNES, 1839) -- Blacktip shark. Uncommon Pungo River tailings Confidence: low-medium \| based on isolated tooth-positions Extant: Circumglobal, subtropical Purdy et al (2001) do not include this tooth-design.
	C. macloti (MÜLLER & HENLE, 1839) -- Hardnose shark. Abundant in Pungo River sands Confidence: Very high \| Upper reconstruction conforms with Recent tooth-set, lower teeth well represented Extant: Indian Ocean and western Pacific Purdy et al (2001): PR Units 1-5 & YT (unit 1, ?redeposit)
	C. perezii (POEY, 1876) -- Caribbean Reef Shark Abundant in Pungo River, common in Yorktown Confidence: Very high \| Upper reconstruction conforms with Recent tooth-set, lower teeth represented Extant: Western Atlantic, subtropical Purdy et al (2001): Pungo River units 3-5 and Yorktown Unit 1
	Carcharhinus plumbeus (NARDO, 1827) -- Sandbar shark Uncommon in Pungo River, common in Yorktown Confidence: High \| Upper reconstruction conforms with Recent tooth-set Extant: Scattered circumglobal, subtropical Purdy et al (2001): Pungo River units 4,5); Yorktown unit 1
Additional tooth-designs that could not be attributed to the above taxa are present in Pungo River tailings (a project for the future).
YORKTOWN FM. (Pliocene) The cooler waters of the Pliocene were home to sharks and rays that currently inhabit today's North Carolina waters;
	*C. cf galapagensis* (SNODGRASS & HELLER, 1905) Galapagos shark Relatively rare in the Yorktown and possibly from the Pungo River. Confidence: Low-Med \| Represented by a few isolated teeth and based on tooth-design only Extant: Circumglobal, Tropical-subtropical Purdy et al (2001) do not include this species in the fauna.
	*C. leucas* (VALENCIENNES, 1839) -- Bull shark Uncommon in the Yorktown, (smaller & less common in the PR). Confidence: medium-high \| Awaits tooth-set reconstruction Extant: Circumglobal, subtropical Purdy et al (2001) rare in PR units 1-5, common in YT units 1-3.
	*C. cf longimanus* (POEY, 1861) -- Oceanic Whitetip shark Unommon in the Yorktown. Confidence: low-med \| Awaits verification Extant: Circumglobal, temperate-subtropical Purdy et al (2001) assigned this design to C. leucas.
	C. obscurus (LeSUEUR, 1818) -- Dusky shark Most abundant gray shark in the Yorktown. Confidence: high \| Upper reconstruction conforms with Recent tooth-set, lower teeth represented. Extant: Circumglobal, temperate-subtropical Purdy et al (2001) reported from Yorktown units 1-3.
	C. perezii (POEY, 1876) -- Caribbean Reef Shark Abundant in Pungo River, common in Yorktown Confidence: Very high \| Upper reconstruction conforms with Recent tooth-set, lower teeth represented Extant: Western Atlantic, subtropical Purdy et al (2001): Pungo River units 3-5 and Yorktown Unit 1
	Carcharhinus plumbeus (NARDO, 1827) -- Sandbar shark Uncommon in Pungo River, common in Yorktown Confidence: High \| Upper reconstruction conforms with Recent tooth-set Extant: Scattered circumglobal, subtropical Purdy et al (2001): Pungo River units 4,5); Yorktown unit 1
Additional tooth-designs that could not be attributed to the above taxa are present in Yorktown tailings.

Aknowledgements

Attempting to make any sense of the Carcharhinus fossil record is an ugly (capital "U") task and impossible without the help of many others. Accessing the published record is difficult, but with the help of Pieter De Schutter, René Kindlimann, Earl Manning, David Ward and Google, the pieces came together. Gordon Hubbell was very helpful in providing jaws from which tooth-sets could be removed and access to his collection of Western Sahara material. The hands-on experience of Mark Harris and Bill Heim was equally if not more important, especially when correlating the fossil and Recent records.

Footnotes

A	German translation courtesy of René Kindlimann.
B	Fishbase includes Carcharhinus menisorrah (MÜLLER & HENLE, 1839) as having been synonymized with C. falciformis.
C	"The teeth are probably from the upper Cretaceous or Miocene beds [the Navesink-Hornertown bed marl, the Manasquan marl, the Kirkwood formation, K.] though no such information is given on any of the labels." New Jersey locales included Monmouth, Burlington. Gloucester, and Salem Counties.
D	I really have no idea what he is trying to say; if anyone understands the underlying thought process/intent of this statement, I'm open to suggestions.
E	Prionodon lamia is now regarded a junior synonym of Carcharodon carcharias.
F	At the time of this paper, the Trent Marls were thought to be Miocene.
G	This last statement is 'interesting' in that Whitley (1940) designated queenslandicus the type species for Negaprion, although it is junior to Aprionodon acutidens (RÜPPELL, 1837).
H	Interestingly, the Recent Isogomphodon maculipinnis POEY, 1865 was found to be a junior synonym of C. brevipinna. Bill Heim (pers com 2001) referred to similar Oligocene teeth from Virginia as brevipinna-lineage.
I	Bill Heim (pers. com. Mar 2009) notes that the angular mesial edge of figures 5a & b is "a common pathology" seen in Carcharhinus obscurus.

Selected References

S. Adnet, S., Antoine, P., Hassan Baqri, S., Crochet, J., Marivaux, L. Welcomme, J. and Métais, G., 2007. New tropical carcharhinids (chondrichthyes, Carcharhiniformes) from the late Eocene-early Oligocene of Balochistan, Pakistan: Paleoenvironmental and paleogeographic implications. Journal of Asian Earth Sciences 30 (2007) 303-323.
Agassiz, L. 1843. Recherches sur les Poissons Fossiles, Vol. 3. Contenant l'histoire de l'Ordre des Placoides (Text), Neuchâtel, vii, 1-390, 1-32. Vol. 3. Atlas, 83 plates.
Arambourg, C., 1952. Les Vertébrés fossiles des Gisements de Phosphates (Maroc-Algére-Tunisie), - Service Géol. Maroc, Notes et Mém., 92, pp 1-372.
Bigelow, H. and W. Schroeder 1948. Part 1. Sharks; in: Fishes of the western North Atlantic. Sears Foundation for Marine Research, Yale University, New Haven.
Cappetta, H., 1987. Chondrichthyes II: Mesozoic and Cenozoic Elasmobranchii. Handbook of Paleoichthyology, 3B. Gustav Fischer Verlag, Stuttgart and New York, 193 pp.
Case, G., 1980. A Selachian Fauna from the Trent Formation, Lower Miocene of Eastern North Carolina In: Palaeontographica, 171:75-103.
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. and Cappetta, H., 1990, The Eocene Selachian Fauna from the Fayum Depression in Egypt. Palaeontographica Abt. A, 212: 1-30.>
Cope, E., 1867. An addition to the Vertebrate Fauna of the Miocene period, with a synopsis of the extinct Cetacea of the United States. Proceed. Acad. Nat. Sciences of Philadelphia pp 138-155.
Dames, W. 1883. Über eine tertiäre Wirbelthierfauna von der westlichen Insel des Birket-el-Qurun im Fajum (Aegypten), Sitzungsberichte der Königlich Preussischen Akademie der Wissenschafter zu Berlin: 129-153.
Eastman, C., 1901. Pisces. In: eds. Clark, W. & Martin, F. Eocene Depositis of Maryland . Maryland Geologocal Survey, John Hopkins Univ Press, Baltimore pp 98-115 4 pls.
Eastman, C., 1904. Pisces. In: Maryland Geologocal Survey - Miocene. John Hopkins Univ Press, Baltimore 543 pp, 135 pls.
Emmons, E., 1858. Agriculture of the eastern counties; together with descriptions of the fossils of the marl beds. Report, North Carolina Geol. Surv. Printed by H.D. Turner, Raleigh, xvi + 314pp.
Fowler, H., 1911. Cretaceous and Tertiary Fish. A Description of the Fossil Remains of the Cretaceous, Eocene and Miocene Formations of New Jersey;Bulletin 4, Geo. Sur. of NJ. pp 22-192.
Gibbes, R., 1849. Monograph of the fossil Squalidae of the United States. Journal of the Academy of Natural Sciences Philadelphia, (2), 1 (3), pp 191-206.
Hay, O., 1901. Bibliography and Catalogue of the Fossil Vertebrata of North America. Bul of the USGS No. 178, 868pp.
Kent, B., 1994. Fossil Sharks of the Chesapeake Region. Egan Rees & Boyer, Maryland. 146 pp.
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.
Manning, E., 2003. The Eocene/Oligocene transition in marine vertebrates of the Gulf Coastal Plain. Chap 21, pp 366-385. In: Prothero, D, L Ivany and E. Nesbitt (eds), From Greenhouse to Icehouse, the marine Eocene-Oligocene transition; Columbia Univ. Press, NY, xi+541pp.
Müller, A. 1999. Ichthyofaunen aus dem atlantischen Tertiär der USA. Leipziger Geowissenschafteb, Leipzig, 9/10: 1-360.
Naylor, G. and L. Marcus, 1994. Identifying Isolated Shark Teeth of the Genus Carcharhinus to Species: Relevance for Tracking Phyletic Change Through the Fossil Record. American Museum Novtautes, No. 3109, 53 pp.
Priem, F., 1897. Sur les poissons de l'Eocène du Mont Mokattam (Egypte). Bull. Soc. Géol. France, 25: 212-227.
Stromer, E., 1905 Die Fischreste des mittleren ubd oberen Eocäns von Ägypten, I. Die selachier, B. Squaloidei. Beitrag Paleontologische und Geologische Osterreich-Ungarns 18: 163-92.
Ward, D & Weist, 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.
White, E., 1926. Eocene Fishes from Nigeria Bulletin - Geological Survey of Nigeria, 10. pp 1-82.
White, E., 1956 The Eocene Fishes of Alabama. Bulletins of American Paleontology, 36:156 PRI Ithica, NY p123-151
Woodward, A.-Smith, 1889. Catalogue of the Fossil Fishes in the British Museum, vol 1,