Eogmelina, Copilaş-Ciocianu & Ionesi, 2024

Copilaş-Ciocianu, Denis & Ionesi, Viorel, 2024, New Miocene fossil taxa illuminate the evolution and paleobiogeography of the Ponto-Caspian gammaroid amphipod radiation, Contributions to Zoology 93, pp. 268-288 : 275-276

Genus † Eogmelina gen. nov.

Zoobank LSID urn:lsid:zoobank.org:act:89D84AB9-3C24-4B60-BE3C-D0B81C35FEA0

Zoobank publication LSID: urn:lsid:zoobank.org:pub:18AD77A2-5812-4C84-B93C-8BB527ADEF38

Type species. † Eogmelina moldavica gen. et sp. nov. ( fig. 5 )

Other species. † Eogmelina prisca gen. et sp. nov. ( fig. 6 )

Diagnosis. Body tall and robust (up to 22 mm length) with or without dorsal pleonal projections, lateral pereonal projections absent, coxal plates I-III taller than wide, urosomites free and devoid of humps and tubercles. Antenna 1 peduncle short, not extending beyond the distal end of the 4th peduncular segment of antenna 2. The 3rd peduncular segment of antenna 2 is shorter than half the length of the 4th segment; 4th segment length subequal to head length. Propodi of gnathopods 1–2 similar in size and shape, rectangular, moderately developed, palm length subequal to posterior margin. Pereopods 3–7 robust and well developed, dactyli moderately developed and relatively straight. Pereopods 3–4 carpus longer than wide, not expanded. Length of pereopod 7 exceeds 0.4 of body length. Pereopod 7 basis taller than wide, posterior margin convex, without postero-distal lobe. Epimeral plates 2–3 with acute postero-inferior corners. Uropod 3 extends beyond the distal end of uropod 1, endopod/exopod ratio is 0.9.

Differential diagnosis. Eogmelina gen. nov. can be readily distinguished from the fossil Ponto-Caspian genera Praegmelina and Andrussovia by the following characters: 1) combined length of antenna 2 peduncle segments 4 and 5 longer than head length (vs. shorter), 2) antenna 1 peduncle not reaching the distal end of the 4th peduncular segment of antenna 2 (vs. extending beyond it) (see key).

Etymology. Derived from the Greek word eos (dawn), referring to its early appearance and plesiomorphic morphology, and the name of the extant genus Gmelina Sars, 1894 , to which it bares a superficial resemblance.

Figures

FIGURE 5 †Eogmelina moldavica gen. et sp. nov.On the right are interpretative drawings of the corresponding fossils on the left.(A) Holotype male and paratype female (inventory No. 8236,Vlădiceni quarry), (B) male (inventory No.8237,Vlădiceni quarry), (C) female (inventory No.8238, Iași City), (D) female (inventory No.8239, Vlădiceni quarry).Scale bars = 1 mm. Abbreviations:A = antenna; B = basis; C = coxa; G = gnathopod; H = head; P = pereonite; PL = pleonite; PP = pereopod; U = urosomite; UP = uropod; T = telson.

FIGURE 6 †Eogmelina prisca gen.et sp. nov.On the right are interpretative drawings of the corresponding fossils on the left.(A) Holotype male (inventory No. 8241,Vlădiceni quarry), (B) paratype male (inventory No. 8242, Iași City), (C) disarticulated remains of unknown sex (inventory No.8243,Vlădiceni quarry).Scale bars = 1 mm.Abbreviations:A = antenna; B = basis; C = coxa; G = gnathopod; H = head; P = pereonite; PL = pleonite; PP = pereopod; U = urosomite; UP = uropod; T = telson.