http://www.collembola.org/key/pseurida.htm - Last updated on 2009.09.30 by Frans Janssens
Checklist of the Collembola: Key to the species of Pseudanurida

This key is still under construction. Note that missing figures will be provided as soon as possible. Currently, the key is in the feasibility study phase to find out how to integrate in the checklist in a modular way a key that has been generated with DELTA.

Rationale

The rationale for taxa used and not used as well as subtaxonomic classification for some taxa is to be provided.

Key

Note that no distinction between subtaxa and taxa is made in the key. 

1(0). Claw with appressed tooth more distal in position or without;
        dens with 6 setae; dorsal lobe of sixth abdominal segment
        without ventral setae; epipharynx apically cleft; fifth
        abdominal segment with a ventral single row................. 2
      Claw with strong basal tooth; dens with 12 setae; dorsal lobe of
        sixth abdominal segment with many ventral setae; epipharynx
        square-ended; fifth abdominal segment with many ventral setae
        before the genital field........................ billitonensis
 
2(1). Head with strongly differentiated macrochaetae; sixth abdominal
        segment with many setae on dorsal valve, including median
        unpaired setae in the anterior and posterior rows; ventral
        tube without setae on the valves............... bogoyawlenskyi
      Head without strongly differentiated macrochaetae; sixth
        abdominal segment with 3 + 3 dorsal setae, median unpaired
        setae absent; ventral tube with 1 + 1 setae placed far
        anteriorly on the valves.................................... 3
 
3(2). Mucro with posterior lamella supported by a toothlike strut;
        sixth abdominal segment tapered cylindrical, without
        differentiation into dorsal and lateral anal valves, although
        the corresponding seta tracts are clearly distinguishable;
        tegumental bleeding sites present on head, first abdominal
        segment and fourth abdominal segment; tenaculum with both
        anterior and posterior lobes of corpus elevated beyond rami...
         ........................................................ yini
      Mucro without supporting strut on posterior lamella; sixth
        abdominal segment with dorsal and ventral anal valves clearly
        separated by indentations; tegumental bleeding sites not
        differentiated; tenaculum with only the anterior lobe
        elevated.................................................... 4
 
4(3). Setae p2 on fifth abdominal segment and p3 on first to third
        abdominal segment more than 2 times length of other setae;
        general body setae short; third antennal segment and fourth
        antennal segment short and compact; males with sixth abdominal
        segment as in female................................. sawayana
      Setae p2 on fifth abdominal segment and p3 on first to third
        abdominal segment not longer then other setae; general body
        setae strong; third antennal segment and fourth antennal
        segment elongate in adult; males with sixth abdominal segment
        greatly elongate..................................... glauerti

Differential diagnoses

billitonensis
Claw with strong basal tooth. Dens with 12 setae. Dorsal lobe of sixth abdominal segment with many ventral setae. Epipharynx square-ended. Fifth abdominal segment with many ventral setae before the genital field. Mandible with numerous, even teeth. Maxilla with 2 rudimentary lamellae. Sense organ of third antennal segment distal. Superlinguae with about 20 strong inner teeth. Tergal chaetotaxy all tergites with dense setae in several rows.

bogoyawlenskyi
Claw with appressed tooth more distal in position or without. Dens with 6 setae. Dorsal lobe of sixth abdominal segment without ventral setae. Epipharynx apically cleft. Fifth abdominal segment with a ventral single row. Head with strongly differentiated macrochaetae. Mandible with 2 large lamelliform proximal teeth and a number of smaller distal teeth. Maxilla without lamellae. Sense organ of third antennal segment proximal. Sixth abdominal segment with many setae on dorsal valve, including median unpaired setae in the anterior and posterior rows. Superlinguae with fewer teeth. Tergal chaetotaxy reduced and forming a single row on prothorax and fifth abdominal segment. Ventral tube without setae on the valves.

glauerti
Claw with appressed tooth more distal in position or without. Dens with 6 setae. Dorsal lobe of sixth abdominal segment without ventral setae. Epipharynx apically cleft. Fifth abdominal segment with a ventral single row. General body setae strong. Head without strongly differentiated macrochaetae. Males with sixth abdominal segment greatly elongate. Mandible with 2 large lamelliform proximal teeth and a number of smaller distal teeth. Maxilla without lamellae. Mucro without supporting strut on posterior lamella. Sense organ of third antennal segment proximal. Setae p2 on fifth abdominal segment and p3 on first to third abdominal segment not longer then other setae. Sixth abdominal segment with dorsal and ventral anal valves clearly separated by indentations. Sixth abdominal segment with 3 + 3 dorsal setae, median unpaired setae absent. Superlinguae with fewer teeth. Tegumental bleeding sites not differentiated. Tenaculum with only the anterior lobe elevated. Tergal chaetotaxy reduced and forming a single row on prothorax and fifth abdominal segment. Third antennal segment and fourth antennal segment elongate in adult. Ventral tube with 1 + 1 setae placed far anteriorly on the valves.

sawayana
Claw with appressed tooth more distal in position or without. Dens with 6 setae. Dorsal lobe of sixth abdominal segment without ventral setae. Epipharynx apically cleft. Fifth abdominal segment with a ventral single row. General body setae short. Head without strongly differentiated macrochaetae. Males with sixth abdominal segment as in female. Mandible with 2 large lamelliform proximal teeth and a number of smaller distal teeth. Maxilla without lamellae. Mucro without supporting strut on posterior lamella. Sense organ of third antennal segment proximal. Setae p2 on fifth abdominal segment and p3 on first to third abdominal segment more than 2 times length of other setae. Sixth abdominal segment with dorsal and ventral anal valves clearly separated by indentations. Sixth abdominal segment with 3 + 3 dorsal setae, median unpaired setae absent. Superlinguae with fewer teeth. Tegumental bleeding sites not differentiated. Tenaculum with only the anterior lobe elevated. Tergal chaetotaxy reduced and forming a single row on prothorax and fifth abdominal segment. Third antennal segment and fourth antennal segment short and compact. Ventral tube with 1 + 1 setae placed far anteriorly on the valves.

yini
Claw with appressed tooth more distal in position or without. Dens with 6 setae. Dorsal lobe of sixth abdominal segment without ventral setae. Epipharynx apically cleft. Fifth abdominal segment with a ventral single row. Head without strongly differentiated macrochaetae. Mandible with 2 large lamelliform proximal teeth and a number of smaller distal teeth. Maxilla without lamellae. Mucro with posterior lamella supported by a toothlike strut. Sense organ of third antennal segment proximal. Sixth abdominal segment tapered cylindrical, without differentiation into dorsal and lateral anal valves, although the corresponding seta tracts are clearly distinguishable. Sixth abdominal segment with 3 + 3 dorsal setae, median unpaired setae absent. Superlinguae with fewer teeth. Tegumental bleeding sites present on head, first abdominal segment and fourth abdominal segment. Tenaculum with both anterior and posterior lobes of corpus elevated beyond rami. Tergal chaetotaxy reduced and forming a single row on prothorax and fifth abdominal segment. Ventral tube with 1 + 1 setae placed far anteriorly on the valves.

References