A new cochliodont anterior tooth plate from the Mississippian of Alabama (USA) having implications for the origin of tooth plates from tooth files

Table 1 Key specimens with taxonomy, ages, and features

Specimen	Fig.	Original designation	Current designation	Taxonomic group	Age	Features
NHMUK PV P8216	2	Helodus simplex	Helodus simplex	Helodontidae	Pennsylvanian	Tooth file, teeth mesiodistallly expanded and bilaterally symmetric or nearly so
NHMUK PV P1415	3	Pleurodus rankinii	Pleuroplax rankinei	Helodontidae	Pennsylvanian	Tooth plate with crenulated edges, bilaterally symmetric
USNM V3518	12	Helodus coxanus	Helodus coxanus	Cochliodontiformes?	Mississippian (early Viséan)	Tooth file, crowns triangular, mesiodistally compressed, bases fused, bilaterally symmetric
ALMNH PV 2016.0002.0002	9	Arcuodus multicuspidatus	Arcuodus multicuspidatus	Cochliodontiformes	Mississippian (late Serpukhovian)	Tooth plate with sharp median ridge, sharp cusps, bilaterally symmetric or nearly so
USNM V13017	6	Deltodopsis? bialveatus	Arcuodus bialveatus	Cochliodontiformes	Mississippian (late Tournasian)	Tooth plate with low, irregular bulges, not bilaterally symmetric
AMNH FF6450	7	Deltodopsis? bialveatus	Arcuodus bialveatus	Cochliodontiformes	Mississippian (early Viséan)	Tooth plate with low, wide, transverse ridges, not bilaterally symmetric
USNM V13015	10	Deltodopsis? convexus	Arcuodus bialveatus	Cochliodontiformes	Mississippian (late Tournasian)	Tooth plate with very low surface undulations, bilaterally symmetric or nearly so

ISSN: 2056-306X