Fig 1.
A map of Albian-age rocks in Tarrant County, Texas, showing the approximate location of OMNH V1727.
Fig 2.
A stratigraphic column at V1727.
Fig 3.
Additional shark vertebrae found in situ in the same locality as OMNH 68860.
The surrounding lithology correlates with the indurated limestone bedforms 10.5 m above the base of the measured section (photo courtesy of L. Hall, 2013).
Fig 4.
OMNH 68860 in (descending order) rostral, caudal, ventral, right lateral, dorsal, and left lateral views.
Fig 5.
Reconstruction of the large lamniform sharks from the Duck Creek Formation and Kiowa Shale.
KUVP 16343 and OMNH 68860 are both reconstructed as Leptostyrax macrorhiza and modeled after an odontaspidid. This reconstruction was based on dental similarities shared between Eoptolamnidae and Odontaspididae [14]. Both specimens represent the smallest calculated estimate based on the formula of Shimada [2]. Cretalamna appendiculata is reconstructed as a classic lamnid shark based on shared dental patterns between this genus and members of the family Lamnidae [26].