Alphacheles zeta Klompmaker & Martin & Hyžný & Bowman & Phillips & Portell 2025, n. comb.

Alphacheles zeta (Rathbun, 1936) n. comb. (Figs 5; 6) Callianassa zeta Rathbun, 1936: 37. — Feldmann et al. 2019: 284, 293, 294, fig. 3E, F. Callianassa alpha Rathbun, 1935a: 67, pl. 15.23-15.25, 15.27. — non Callianassa alpha Stenzel, 1935: 391, pl. 15.1, 15.2, 15.7, 15.8. TYPE MATERIAL. — Holotype. United States • Alabama, Wilcox County, Prairie Creek region; Porters Creek Formation; Paleocene (upper Danian); USNM MO 371506. Paratypes. United States • 1 specimen; same as for the holotype; USNM PAL 336022 A • 10 specimens; idem; USNM PAL 336022 B. ADDITIONAL MATERIAL EXAMINED. — United States • 1 specimen; Alabama, Lowndes County, Mussel Creek roadcut (31°58’17”N, 86°42’15”W), ALMNH loc. 3; Clayton Formation, Pine Barren Member, lower middle NP2 nannofossil zone; Paleocene (lower Danian); ALMNH: Paleo:21511 (propodus) • 1 specimen; idem; ALMNH: Paleo:21512 (propodus) • 1 specimen; idem; ALMN-H: Paleo:21513 (propodus) • 2 specimens; idem; MMNS IP-7255 (2 specimens, partial propodus and dactylus and propodus and dactylus) • 1 specimen; idem; UF 303822 (propodus). TYPE HORIZON. — Porters Creek Formation (Sucarnoochee beds in Rathbun 1935a), upper Danian. TYPE LOCALITY. — Prairie Creek region, Wilcox County, Alabama, United States. DIAGNOSIS. — Major cheliped propodus palm slightly longer than high (L/H = 1.1-1.3), upper and lower margins carinate, subparallel with each other, inner and outer surfaces with densely tuberculate, sharply delineated areas at base of fixed finger, forming part of broad longitudinal ridges; fixed finger approximately 0.7 as long as upper palm length, slender, occlusal surface with continuous row of microdenticles; major cheliped dactylus upper margin convex, occlusal margin sinuous. MEASUREMENTS. — Palm length in mm: ALMNH:Paleo:21511: c. 5.0, USNM MO 371506: 6.8. DESCRIPTION Major cheliped propodus palm slightly longer than high: 1.1-1.3 as long as high (measured at upper margin), highest at palm mid-length; proximo-lower corner rounded; upper and lower margins subparallel with each other, lower margin with slight concavity at junction with fixed finger; upper and lower margins sharply carinate, carinae accompanied with rows of small setal pores on both sides (inner and outer); outer lateral largely surface smooth, with few setal pores and two densely tuberculated, sharply delineated areas: circular patch of tubercles positioned below articulation with dactylus and oval patch of tubercles forming broad longitudinal ridge at base of fixed finger; inner lateral surface with similar tuberculate longitudinal ridge and several scattered tubercles close to articulation with dactylus. Fixed finger approximately 0.7 as long as upper palm length, slender, subcircular in cross section, distal half bent slightly upward; occlusal surface with continuous row of microdenticles. Major cheliped dactylus upper margin convex; outer and inner lateral surfaces with rows of setal pores along upper margin and occlusal margin; occlusal margin sinuous forming elongate convexity proximally and slightly shorter concavity distally. Minor cheliped propodus palm 1.4 as long as high (measured at upper margin), upper and lower margin subparallel; fixed finger presumably as long as palm, occlusal surface with one tooth at mid-length; dactylus slender, occlusal margin continuous. REMARKS Rathbun (1935a: pl. 15.23-15.25, 15.27) figured two specimens, one of which is the holotype (USNM MO 371506). The Smithsonian Institution assigned USNM PAL 336022 A to the figured propodus considered a paratype and USNM PAL 336022 B to 10 other paratype propodi specimens, verified by AAK in 2018. This totals 12 specimens rather than the 11 specimensRathbun (1935a) mentioned.