Paralbula marylandica Blake, 1940
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https://doi.org/ 10.4202/app.01117.2023 |
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https://treatment.plazi.org/id/03E18741-130F-EF0C-DF68-FCCAFF32FE2D |
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Felipe |
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Paralbula marylandica Blake, 1940 |
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Paralbula marylandica Blake, 1940
Fig. 3D View Fig .
Material.—Twenty-eight teeth (for repository numbers see SOM 1: table 1): five from the lower Hornerstown Formation below the MFL, seven from the MFL, six from the lower Hornerstown Formation above the MFL, and ten collected as float. All from the Maastrichtian-Danian Hornerstown Formation, Edelman Fossil Park, Mantua Township, New Jersey, USA.
Description.—The teeth are roughly circular in occlusal view and hemispherical in form. The enamel of each tooth is smooth, and many exhibit fairly thin enamel structure when viewed in profile. A basilar foramen is present in several complete specimens. A few specimens consist of only the enamel cap, with the underlying dentine broken away/not preserved. One specimen consists solely of a dentine core. All specimens range ~0.5– 2 mm in diameter.
Remarks.—The hemispherical shape of the teeth, in combination with possession of a basilar foramen (in some specimens), identify them as pertaining to a paralbuline fish ( Estes 1969). Their round shape in occlusal view is more consistent with Paralbula than Pseudoegertonia , the only other genus within Paralbulinae Estes, 1969. Further, the smooth, unornamented enamel of these teeth is consistent with Paralbula marylandica Blake, 1940 , but differs from the condition in the only other known Paralbula species from North America, Paralbula casei Estes, 1969 , which exhibits intricate and often radiating sculpturing of the enamel surface ( Estes 1969).
As all other previously-described specimens of this taxon derive from the Paleocene and Eocene ( Blake 1940; Estes 1969; Ebersole et al. 2019; Schein et al. 2011), our recovery of teeth in Hornerstown sediments beneath the MFL constitutes a range extension for Paralbula marylandica back into the latest Maastrichtian, indicating it survived the K/Pg mass extinction.
Stratigraphic and geographic range.— Upper Cretaceous (Maastrichtian) to lower Eocene (Lutetian) of Alabama, Arkansas, Maryland, New Jersey, Texas, and Virginia in USA .
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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