Stammericaris, Jakobi, 1972

Taxonomic key for the identification of males of the know species of Stammericaris View in CoL

* species description and illustrations not consistent with the current morphological details requirements. Modified from Bruno et al. (2023)

1. P4 endopod a curved plate with a pointed inner tip carrying at its outer border 1 or 2 outgrowths, the distal one being a feathered or plain seta; caudal rami sub-cylindrical, usually longer than last abdominal somite................................ 2

- P4 endopod approximately cylindrical, distally enlarged in two/ three protrusions; caudal rami sub-cylindrical, slightly shorter than last abdominal somite............................................................................. 3

2. P3 exp-1 with longitudinal rows of spinules on outer margin................................................... 5

- P3 exp-1 without longitudinal rows of spinules on outer margin............................................... 17

3. P4 endopod approximately cylindrical, distally enlarged in two protrusions......................... S. galichiai sp. nov.

- P4 endopod approximately cylindrical, distally enlarged in three protrusions...................................... 4

4 P1 basis with hook on inner margin; P3 exp-1 with longitudinal row of two spinules proximally on outer margin; P4 basis with two spiniform processes of different size on inner margin, the one closest to the endopod is the largest; P4 endopod represented by a small cylindrical segment, as long as ½ of the corresponding exp-1, with three small apical protrusions.... S. destillans

- P1 basis with hook and spinule on inner margin; P3 exp-1 with longitudinal row of three spinules proximally on outer margin; P4 basis with two spiniform processes of different size on inner margin, the one closest to the endopod is the smallest; P4 endopod represented by a small cylindrical segment, apically bent at 90°, slightly longer than ½ of the corresponding exp-1, with three small apical protrusions............................................................... S. similior

5 Caudal rami with pointed dorsal distal apophysis.............................................................6

- Caudal rami without pointed dorsal distal apophysis......................................................... 9

6 Caudal rami sub-cylindrical, shorter than last abdominal somite. P1 basis with one spinule on inner margin..... S. lorenzae

- Caudal rami sub-cylindrical, shorter than last abdominal somite. P1 basis with one spinule and one hook on inner margin...7

7 P3 exp-1 with proximal row of two stronger, and distal row of five thinner, longitudinal spinules on outer margin; enp P4 slightly shorter than the first two segments of the corresponding exp, the inwardly curved inner tip with lateral pinnate expansion.............................................................................................. S. pasquinii

- P3 exp-1 with proximal row of two and distal row of four longitudinal spinules on outer margin; enp P4 as long as or slightly longer than the corresponding exp-1, the inwardly-curved inner tip apically bilobate.................................8

8 P1 basis with spinule and longer hook on inner margin; P3 exp-1 with proximal row of two spinules, distal row of four longitudinal spinules, all of them of similar size, on outer margin; P4 basis with three processes with blunt tip on inner margin, the medial-most much larger than the other ones.................................................. S. diversitatis

- P1 basis with spinule and hook of similar length on inner margin; P3 exp-1 with proximal row of two spinules, and distal row of two larger and two smaller spinules (almost divided in two groups), on outer margin; P4 basis with four spinules on inner margin, the distalmost from the endopod is transversally inserted, the remaining ones decrease in size from inner to outer........................................................................................ .. S. vincentimariae

9 Caudal rami cylindrical and narrow, not tapering, longer than the last abdominal somite; enp P4 slightly longer than the corresponding exp-1, with only inner tip and apical pinnate outgrowth (proximal spiniform outgrowth missing)..........10

- Caudal rami sub-cylindrical and narrow, tapering distally, shorter than the last abdominal somite; enp P4 of different shape.. .................................................................................................. 11

10 P5 with spine on inner corner.................................................................... S. nertensis

- P5 with tip on inner corner..............................................................................16

11 P4 basis, inner margin with three spinules increasing in length from outer to inner one.............................. 12

- P4 basis with only one spinule on the inner margin.......................................................... 14

12 Exp-2 apophysis much longer than thumb.........................................................* S. phreatica

- Exp-2 apophysis slightly longer than thumb............................................................... 13

13 P3 exp-1, outer margin with proximal longitudinal row of two spinules and distal longitudinal row of six spinules, all of same length; enp P4 longer than the corresponding exp-......................................... * S. stammeri stammeri

- P3 exp-1, outer margin with proximal and distal longitudinal row of two spinules all of same length; enp P4 as long as the corresponding exp-1......................................................................... S. amyclaea

14 P3 exp-1, outer margin with proximal row of three spinules and distal row of four spinules; P4 basis with one thin and straight spinule on the inner margin................................................................... * S. acherusia

- P3 exp-1, outer margin with two longitudinal rows of spinules, both inserted in the proximal half of the outer margin; P4 basis with one large, inwardly-curved spinule on the inner margin.................................................. 15

15 Urosomites not pitted. P3 exp-1, outer margin with proximal and distal longitudinal row of two spinules; enp P4 represented by plate curved inwards in an almost L-shape, with strongly bifid tip; P4 exp-1 characteristically enlarged and strongly bent inwards................................................................................ S. remotaepatriae

- Urosomites pitted (character present only in this species); P3 exp-1, outer margin with proximal row of three or four spinules and distal row of four spinules; P4 endopod of different shape; P4 slightly enlarged at base and straight....... S. palmerae

16. Caudal rami much longer than anal somite; thumb on P3 narrow and sinuous, ending in three tips............. S. triphyda

-. Caudal rami much longer than anal somite; thumb on P3 short and straight, ending in one tip................... S. orcina

17. P4 basis ornamented with one short seta and two spinules of same length and slightly curved outwards aligned along inner margin..................................................................................... S. trinacriae

- P4 basis ornamented with two spinules of different length and slightly curved outwards aligned along inner margin..................................................................................................... S. balcanica