Tanystylum tayronae, Müller & Krapp, 2009

Müller, Hans-Georg & Krapp, Franz, 2009, The pycnogonid fauna (Pycnogonida, Arthropoda) of the Tayrona National Park and adjoining areas on the Caribbean coast of Colombia 2319, Zootaxa 2319 (1), pp. 1-138 : 39

Tanystylum Miers, 1879

1. Trunk at base of abdomen with a hemispherical tubercle ................................................................... T. tayronae n.sp. Trunk without such a tubercle....................................................................................................................................... 2

2. Proboscis robust, its distal quarter terminating in a narrow short tube which measures about 1/4 of proximal diameter; crurigers with 1 or 2 spherical tubercles, coxa 1 of all legs with 3 spherical tubercles .......... T. acuminatum Proboscis different ....................................................................................................................................................... 3

3. Crurigers without any distal tubercles .......................................................................................................................... 7 At least crurigers 3–4 with flat distal tubercles............................................................................................................ 4

4. Proboscis very slender, the distal two thirds a narrow tube; coxae1 of all legs with 3 distal tubercles; antero-lateral tubercle on coxae 1 not rounded and distally not forked ........................................................................ T. tubirostrum 1 Proboscis in its proximal half more robust, antero-lateral tubercles on first coxae different ...................................... 5

5. Proboscis in its proximal half a slender tube; coxae 1 of all legs adorned with 3 sphaerical tubercles ...... T. isabellae Proboscis robust, distally obtuse or or attenuted in its distal third ............................................................................... 6

6. Proboscis distally obtuse, continuously and feebly narrowing; antero-lateral tubercles of first coxae normally tripartite ................................................................................................................................................... T. hummelincki Proboscis in distal third strongly narrowing, antero-lateral and dorso-distal tubercles on coxae 1 of all legs sphaerical ................................................................................................................................................................... T. isthmiacum

7. Cheliphores fused at base, palps 4-articled .................................................................................................. T. geminum Cheliphores not fused, palps 6-articled ......................................................................... T. paramexicanum n.sp. (fem.)

† This species has not yet been found on the Caribbean coast of Colombia, even if that region is included in its distribution area. As the species might be easily confounded with T. isabellae it is included in this key to show the characters needed to differentiate between the two.