Palaeogaleus vincenti ( Daimeries, 1888 )
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https://doi.org/ 10.4202/app.01117.2023 |
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https://treatment.plazi.org/id/03E18741-1306-EF03-DF1E-FB77FB17FE2C |
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Felipe |
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Palaeogaleus vincenti ( Daimeries, 1888 ) |
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Palaeogaleus vincenti ( Daimeries, 1888)
Fig. 2A View Fig .
Material.—Seventeen teeth: one lateral tooth (RU-EFP-00284-1) from the upper Navesink Formation; one anterior tooth (RU-EFP-00268-1) from the lower Hornerstown Formation below the MFL; two anterior teeth (RU-EFP-00248-1 and 00254-1) from the MFL; one anterior tooth (RU-EFP-04143) and four lateral teeth (RU-EFP-00158-1, 00225-1, 00233-1, and 00238-1) from the lower Hornerstown Formation above the MFL. The remainder (RU-EFP-04144, 04145, and 00157-1–00157-6) were collected as float. All from the Maastrichtian Navesink and MaastrichtianDanian Hornerstown formations, Jean and Ric Edelman Fossil Park, Mantua Township, New Jersey, USA.
Description.—The principal cusp is broad, strongly convex lingually, labiolingually thick, and angled slightly apicodistally in anterior teeth; in lateral teeth, it is more strongly apicodistally directed. The mesial and distal cutting edges are smooth. Distal cusplets vary in distinction and range from one to four in number. The first distal cusplet is generally around one-third the height of the principal cusp, and succeeding distal cusplets (when present) are shorter. Mesial cusplets range from one to four in number on anterior teeth, and are generally absent in lateral teeth (cf. Cappetta 1987: fig. 100D). Only one of the lateral teeth possesses a subtle, undulating peak along the mesial heel. In lateral teeth, the distal heel is shorter than the mesial heel. The labial base of the crown strongly overhangs the root in all specimens preserving roots, and appears to curl lingually in the same manner in specimens lacking the root. Coarse vertical costules cover the entire labial crown base on most specimens, as well as basal portions of each heel on the lingual face; however, a single lateral and anterior tooth each exhibit nearly smooth labial heels. The basal border of the crown ranges from flat to slightly concave. The root is labiolingually thick and holaulacorhizid in structure, with a deep central groove vertically traversing the lingual protuberance. A small, circular pit occupies the center of this groove on the lingual face in six of the specimens. Where preserved, lateral branches of the root are broad and have flat, wide basal faces.
Remarks.—These teeth can be assigned to Palaeogaleus owing to strong overhang of the labial crown base over the root, the strongly convex lingual face of the principal cusp, relative shortness of the principal cusp, and having a thick, holaulacorhizid root ( Cappetta 1987; Hovestadt and Hovestadt-Euler 2002). Among the eight species of Palaeogaleus currently recognized, the combination of coarse, vertical costules on the labial crown base and overall weak development of mesial and distal cusplets in the Edelman Fossil Park teeth compares best with Palaeogaleus vincenti . Cusplets are generally more well developed in Palaeogaleus havreensis Herman, 1977 , Palaeogaleus dahmanii Noubhani & Cappetta, 1999 , and Palaeogaleus larachei Noubhani & Cappetta, 1999 , and labial crown base ornamentation is absent or poorly developed in Palaeogaleus brivesi Arambourg, 1952 , Palaeogaleus faujasi Geyn, 1937 , and Palaeogaleus prior Arambourg, 1952 Hovestadt and Hovestadt-Euler 2002 ). Also, in contrast to Palaeogaleus prior , Palaeogaleus sublaevis Noubhani & Cappetta, 1999 , and Palaeogaleus larachei ( Hovestadt and Hovestadt-Euler 2002) , the principal cusp is not serrated in any of the RU-EFP specimens. A pit within the midline groove was also described in Palaeogaleus vincenti teeth by Cvancara and Hoganson (1993).
Palaeogaleus vincenti represents a new addition to the fauna of the EFPQ. Case (1996) briefly described 12 specimens of Palaeogaleus vincenti from the lower Hornerstown Formation of Monmouth County, New Jersey, which, at the time, represented the first occurrence of the species in eastern North America. However, the stratigraphic occurrences of Palaeogaleus vincenti teeth from the EFPQ are more precisely constrained and demonstrate that it is present throughout all portions of the lower Hornerstown Formation (specifically above, within, and below the MFL) as well as in the upper Navesink Formation. All previous occurrences, including that described by Case (1996), were from the Paleogene ( Cappetta 2012; Maisch et al. 2020); thus, the two specimens of Palaeogaleus vincenti recovered the Navesink Formation and beneath the MFL in the Hornerstown Formation represent the first Cretaceous occurrences of this species, indicating that Palaeogaleus vincenti evolved before the K/Pg extinction.
Stratigraphic and geographic range.—Upper Cretaceous, Maastrichtian to Paleocene of New Jersey in the USA, Belgium, England, France, and Morocco
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.
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