Key for subfossil taxa in the subtribe Tanytarsina*

*Based on a classification developed by S. Brooks, and discussions with K.P Brodersen, L. Eriksson, H. Olander & I. R. Walker at a 1997 NORD-CHILL Project Workshop in Helsinki, Finland. Compiled by Ian Walker.

Note: This is a tentative key - and could certainly use improvements. Suggestions are very welcome.

NOTES CONCERNING MY TAXONOMY

- a) Mentum very narrow, normally with only 2 pairs of lateral teeth; second lateral teeth set behind the first lateral teeth (Fig. 1, 2)
  .............................................................................. 2. (Corynocera ambigua group)
- b) Mentum broad, with 4 or 5 distinct pairs of lateral teeth (Fig. 3, 4)
  .............................................................................. 3.
- a) Teeth of mentum lightly pigmented; mandible without any teeth; antennal pedestal without an apical projection (Fig. 1)
  .............................................................................. Corynocera ambigua
- b) Teeth of mentum darkly pigmented; mandible with indistinct teeth; antennal pedestal with a small, but distinct apical projection (Fig. 2)
  .............................................................................. Corynocera nr. ambigua (sensu Walker & Mathewes,1988)
- a) Mentum with a 5-part median tooth, and only 4 pairs of lateral teeth (Fig. 3a, b)
  ............................................................................. Cladotanytarsus group A (sensu Pinder & Reiss, 1983)
- b) Mentum with a simple or trifid median tooth, and 5 distinct pairs of lateral teeth (Fig. 4)
  .............................................................................. 4.
- a) Second lateral teeth of mentum distinctly shorter than third lateral teeth (Fig. 4)
  ............................................................................. Cladotanytarsus mancus group (see Pinder & Reiss (1983)
- b) Second lateral teeth of mentum as long, or longer, than third lateral teeth (Fig. 8)
  ............................................................................. 5.
- a) Antennal pedestal with an apical projection (sometimes very weak) (Fig. 8)
  ............................................................................. 6.
- b) Antennal pedestal with no indication of an apical projection (Fig. 15)
  ............................................................................. 9.
- a) Apical projection very long (several times longer than broad) (Fig. 5)
  ............................................................................. 7.
- b) Apical projection short (Fig. 8)
  .............................................................................. 8.
- a) Apical projection blunt; mandible with no surface teeth, 3 inner teeth, and 1 dorsal tooth; premandible bifid (Fig. 7)
  ............................................................................. Micropsectra cf. bidentata group
- b) Apical projection very narrow and sharp; mandible with no surface teeth, 2 or 3 inner teeth, and 1 dorsal tooth; premandible trifid (Fig. 5, 6)
  ............................................................................. Tanytarsus chinyensis group (sensu Hofmann, 1971)
- a) Apical projection short and sharp (Fig. 8); premandible bifid; mandible with no surface teeth, 1 dorsal tooth, and 3 inner teeth; median 3 teeth not as in Tanytarsus sp. C
  ................................................................... Micropsectra atrofasciata/radialis group (see Pinder & Reiss, 1983)
- b) Apical projection short (blunt or sharp, but distinct) ; premandible trifid; mandible with 2 surface teeth, 2 dorsal teeth, and 3 inner teeth; median 3 teeth of mentum prominent, with outer margins of 1st laterals diverging anteriorly (Fig. 9)
  .............................................................................. Tanytarsus sp. C (sensu Hofmann, 1971 & Brooks, pers. comm.)
- c) Apical projection short, blunt, and indistinct (Fig. 10); premandible trifid; mandible with no surface teeth, 1 dorsal tooth, and 2 or 3 inner teeth; median 3 teeth of mentum not as in Tanytarsus sp. C
  .............................................................................. Tanytarsus pallidicornis group (sensu Brooks, pers. comm.)
- a) Median teeth prominent to very prominent (Fig. 11, 12); mandibles with 2 surface teeth, 2 or 3 dorsal teeth, and 3 inner teeth; premandible trifid
  .............................................................................. 10.
- b) Median teeth not very prominent (Fig. 13, 14, 15); mandibles with 0 surface teeth, 1 or 2 dorsal teeth, and 2 or 3 inner teeth; premandible bifid or trifid
  .............................................................................. 11.
- a) One of the two surface teeth very large, obscuring the inner teeth of the mandible; median 3 teeth of mentum set forward on a separate plane relative to the other teeth of the mentum (Fig. 11).
  ............................................................................. Corynocera? oliveri type (sensu Hofmann, 19??; Pinder & Reiss, 1983)
- b) Both surface teeth small, not obscuring the inner teeth of the mandible; median 3 teeth of mentum not set on a separate plane; lateral groups of teeth (i.e., lateral teeth 2 to 5) diverging laterally relative to the median group of 3 teeth (Fig. 12)
  .............................................................................. Tanytarsus lugens group (sensu Hofmann, 1971)
- a) Teeth of mentum usually forming an arch anterior to the ventromental plates, outer margin of 1st lateral teeth slightly incurved (Fig. 13); mandible with 2 inner teeth, and 1 dorsal tooth (Fig. 14); premandible bifid; pecten epipharyngis with 3 or 4 teeth; "median suture" deep and narrowly indented
  .............................................................................. Paratanytarsus group
- b) Teeth of mentum not forming an arch anterior to the ventromental plates; mandible with 2 or 3 inner teeth, and 1 or 2 dorsal teeth
  .............................................................................. 12.
- a) Premandible bifid; mandible with 3 inner teeth (basal tooth vestigial), and 1 dorsal tooth; pecten epipharyngis with at least 9 teeth
  .............................................................................. Micropsectra B group
- b) Premandible trifid; mandible with 2 or 3 inner teeth, and 1 or 2 dorsal teeth
  .............................................................................. 13.
- a) Mandible with 3 inner teeth and 1 dorsal tooth
  .............................................................................. Tanytarsus group B
- b) Mandible with 2 inner teeth, and 1 or 2 dorsal teeth
  ............................................................................. 14.
- a) Mandible with 1 dorsal tooth
  .............................................................................. Tanytarsus group J
- b) Mandible with 2 dorsal teeth
  .............................................................................. Tanytarsus group H