Lepidesthes grandis Kier, 1958
Plate: LeGr-10
Series: Pennsylvanian Group: Strawn Formation: Millsap Lake Formation
Locale: Dennis County: Hood Stage: Moscovian
Length: 20.6 mm (fragment size) Height: 19.6 mm Width: 6.9 mm
Specimen in photo: U.S.N.M. 136464 Paratype
Collector: USGS Survey Plates only
Repository: Paleobiology Dept., NMNH, Smithsonian Institution
HOLOTYPE INFO:
Holotype: USNM 111805 (Kier, 1958).
Locality: 3.25 miles northwest of Millsap, Parker County, Texas.
Stratigraphy: Millsap Lake Formation, Strawn Group.
SYSTEMATIC PALEONTOLOGY – TAXONOMY
Class: Echinoidea Leske, 1778
Subclass: Perischoechinoidea M'Coy, 1849
Order: Echinocystitoida Jackson, 1912
Family: Lepidesthidae Jackson, 1896
Genus: LEPIDESTHES Meek & Worthen, 1868
Species: Lepidesthes grandis Kier, 1958
TYPE SPECIES: Lepidesthes coreyi Meek & Worthen, 1868
DIAGNOSIS
A large Lepidesthes characterized by 16 columns of plates in the ambulacra and 6 columns of plates in the interambulacra at the ambitus. Ambulacra are very wide compared to the narrow interambulacra (Kier, 1958).
STRATIGRAPHICAL OCCURRENCE & DISTRIBUTION
Group: Strawn (equivalent to Allegheny Group in Appalachians).
Formations: Millsap Lake Formation; Grindstone Creek Member.
Stratigraphic Units: Pennsylvanian, Moscovian (Desmoinesian).
Counties: Parker, Hood.
Abundance: Rare; known from fragmentary remains.
DESCRIPTION
(Note: Description derived from the Holotype and Paratypes described by Kier, 1958, as the figured specimen is a fragment).
TOP: Shape: Test subspheroidal (Klem, 1904; Kier, 1958).
Top domed: Not fully preserved in type material, presumed convex.
SIDE: Ambitus: Not specified.
Side shape: Presumed globular/subspheroidal based on genus.
AMB: Amb shape: Very wide; much wider than interambulacra.
Amb arrangement: Composed of 16 columns of small plates at the ambitus (Kier, 1958).
Plating: Plates are hexagonal; imbricating adorally (toward the mouth) (Klem, 1904).
INTERAMB: Width: Narrow.
Arrangement: Composed of 6 columns of plates at the ambitus (Kier, 1958).
Plating: Plates imbricate aborally (toward the apex).
PORE PAIRS: Arrangement: Two pores to each ambulacral plate (Klem, 1904).
Location: Pores are placed centrally within the plate (Kier, 1958).
TUBERCLES: Distribution: Surface covered with small secondary tubercles/granules (Kier, 1958).
GRANULES: Granules number from 18 to 25 on larger interambulacral pieces in related species (Klem, 1904).
FASCIOLE: Absent.
APICAL SYSTEM: Not preserved in type material.
PERIPROCT (ANUS): Not preserved.
PERISTOME (MOUTH): Lantern: Aulodont type (Kier, 1958).
SPINES: Condition: Not preserved in holotype, but likely small and needle-like based on tubercle size.
SPECIMENS STUDIED & CONDITION: Paratype USNM 136464 (Fragment of plates).
ETYMOLOGY
From the Latin grandis (large), referring to the large size of the test and high number of ambulacral columns compared to other species.
REMARKS & COMPARISONS
Remarks: The figured specimen is a fragment of the test plating. As the specimen is incomplete, the generic description by Klem (1904) and Meek & Worthen (1868) is referenced: Lepidesthes is characterized by a subspheroidal test, 6–7 interambulacral columns, and very wide ambulacra with imbricating plates.
Comparisons:
Plate: LeGr-10
Series: Pennsylvanian Group: Strawn Formation: Millsap Lake Formation
Locale: Dennis County: Hood Stage: Moscovian
Length: 20.6 mm (fragment size) Height: 19.6 mm Width: 6.9 mm
Specimen in photo: U.S.N.M. 136464 Paratype
Collector: USGS Survey Plates only
Repository: Paleobiology Dept., NMNH, Smithsonian Institution
HOLOTYPE INFO:
Holotype: USNM 111805 (Kier, 1958).
Locality: 3.25 miles northwest of Millsap, Parker County, Texas.
Stratigraphy: Millsap Lake Formation, Strawn Group.
SYSTEMATIC PALEONTOLOGY – TAXONOMY
Class: Echinoidea Leske, 1778
Subclass: Perischoechinoidea M'Coy, 1849
Order: Echinocystitoida Jackson, 1912
Family: Lepidesthidae Jackson, 1896
Genus: LEPIDESTHES Meek & Worthen, 1868
Species: Lepidesthes grandis Kier, 1958
TYPE SPECIES: Lepidesthes coreyi Meek & Worthen, 1868
DIAGNOSIS
A large Lepidesthes characterized by 16 columns of plates in the ambulacra and 6 columns of plates in the interambulacra at the ambitus. Ambulacra are very wide compared to the narrow interambulacra (Kier, 1958).
STRATIGRAPHICAL OCCURRENCE & DISTRIBUTION
Group: Strawn (equivalent to Allegheny Group in Appalachians).
Formations: Millsap Lake Formation; Grindstone Creek Member.
Stratigraphic Units: Pennsylvanian, Moscovian (Desmoinesian).
Counties: Parker, Hood.
Abundance: Rare; known from fragmentary remains.
DESCRIPTION
(Note: Description derived from the Holotype and Paratypes described by Kier, 1958, as the figured specimen is a fragment).
TOP: Shape: Test subspheroidal (Klem, 1904; Kier, 1958).
Top domed: Not fully preserved in type material, presumed convex.
SIDE: Ambitus: Not specified.
Side shape: Presumed globular/subspheroidal based on genus.
AMB: Amb shape: Very wide; much wider than interambulacra.
Amb arrangement: Composed of 16 columns of small plates at the ambitus (Kier, 1958).
Plating: Plates are hexagonal; imbricating adorally (toward the mouth) (Klem, 1904).
INTERAMB: Width: Narrow.
Arrangement: Composed of 6 columns of plates at the ambitus (Kier, 1958).
Plating: Plates imbricate aborally (toward the apex).
PORE PAIRS: Arrangement: Two pores to each ambulacral plate (Klem, 1904).
Location: Pores are placed centrally within the plate (Kier, 1958).
TUBERCLES: Distribution: Surface covered with small secondary tubercles/granules (Kier, 1958).
GRANULES: Granules number from 18 to 25 on larger interambulacral pieces in related species (Klem, 1904).
FASCIOLE: Absent.
APICAL SYSTEM: Not preserved in type material.
PERIPROCT (ANUS): Not preserved.
PERISTOME (MOUTH): Lantern: Aulodont type (Kier, 1958).
SPINES: Condition: Not preserved in holotype, but likely small and needle-like based on tubercle size.
SPECIMENS STUDIED & CONDITION: Paratype USNM 136464 (Fragment of plates).
ETYMOLOGY
From the Latin grandis (large), referring to the large size of the test and high number of ambulacral columns compared to other species.
REMARKS & COMPARISONS
Remarks: The figured specimen is a fragment of the test plating. As the specimen is incomplete, the generic description by Klem (1904) and Meek & Worthen (1868) is referenced: Lepidesthes is characterized by a subspheroidal test, 6–7 interambulacral columns, and very wide ambulacra with imbricating plates.
Comparisons:
- L. colletti: L. grandis (16 ambulacral columns) differs from L. colletti (White), which has 18–20 rows of ambulacral plates and narrower interambulacra (4–5 columns) (Klem, 1904; Kier, 1958).
