Megalomma, Johansson, 1925

Tovar-Hernández, María Ana & Carrera-Parra, Luis F., 2011, Megalomma Johansson, 1925 (Polychaeta: Sabellidae) from America and other world-wide localities, and phylogenetic relationships within the genus 2861, Zootaxa 2861 (1), pp. 1-71 : 13-14

publication ID

https://doi.org/ 10.11646/zootaxa.2861.1.1

DOI

https://doi.org/10.5281/zenodo.5293039

persistent identifier

https://treatment.plazi.org/id/03CF87C4-2972-126F-FF5C-5CE4FA6E4780

treatment provided by

Felipe

scientific name

Megalomma
status

 

Key to American species of Megalomma

1 Radiolar eyes present only in dorsalmost radioles........................................................... 2

- Radiolar eyes not only in dorsalmost radioles............................................................... 5

2(1) Dorsal collar margins fused to faecal groove ( Fig. 1A View FIGURE 1 ); anterior peristomial ring not exposed ( Fig. 17A, D View FIGURE 17 )...................................................................................... M. modestum ( de Quatrefages, 1866)

- Dorsal collar margins not fused to faecal groove ( Figs 1D View FIGURE 1 , 22E View FIGURE 22 ); anterior peristomial ring exposed ( Figs 1D View FIGURE 1 , 3A View FIGURE 3 , 12A View FIGURE 12 , 22E View FIGURE 22 ). ................................................................................................... 3

3(2) Ventral shield of collar divided transversally in two parts ( Fig. 23D, G View FIGURE 23 ); with caruncle ( Fig. 23H View FIGURE 23 )...................................................................................................... M. pigmentum Reish, 1963

- Ventral shield of collar entire ( Fig. 5C View FIGURE 5 ); caruncle absent....................................................... 4

4(3) Anterior peristomial ring exposed dorsally ( Figs 3A View FIGURE 3 , 5A View FIGURE 5 ); ventral basal flanges absent; inferior thoracic chaetae type B ( Fig. 5G View FIGURE 5 ).......................................................................... M. bioculatum ( Ehlers, 1887)

- Anterior peristomial ring exposed dorsally and laterally ( Figs 12A–C View FIGURE 12 , 13A–B, D View FIGURE 13 ); ventral basal flanges present ( Fig. 13D View FIGURE 13 ); inferior thoracic chaetae type C ( Fig. 1G View FIGURE 1 )............................................ M. gesae Knight-Jones, 1997

5(1) Eyes distributed only in 2–7 pairs of radioles............................................................... 6

- Eyes distributed in most radioles........................................................................ 8

6(5) Spiraled eyes ( Figs 24G–I View FIGURE 24 , 25F–H View FIGURE 25 ); dorsal collar margins rounded posteriorly, showing the anterior peristomial ring partially ( Fig. 24B View FIGURE 24 )................................................................... M. splendidum ( Moore, 1905)

- Spherical eyes ( Figs 7G–H View FIGURE 7 , 11E–F View FIGURE 11 )...................................................................... 7

7(6) Dorsal lappets present ( Fig. 11A View FIGURE 11 ); eyes in seven pairs of radioles (dorsalmost and lateral radioles) ( Fig. 7G–H View FIGURE 7 ).................................................................................... M. fauchaldi Giangrande et al. 2007

- Dorsal lappets absent ( Fig. 7C View FIGURE 7 ); eyes in two pairs of radioles (dorsalmost and fifth dorsal radioles); with a glandular ring on chaetiger 3 ( Fig. 7C View FIGURE 7 )........................................................ M. coloratum ( Chamberlin, 1919)

8(5) Dorsal margins of collar not fused to faecal groove ( Fig. 1D View FIGURE 1 ); anterior peristomial ring exposed dorsally; ocular spots in ventralmost radioles ( Fig. 26G View FIGURE 26 )............................................................. M. georgiense n. sp.

- Dorsal margin of collar fused to faecal groove ( Figs 1A View FIGURE 1 , 16A View FIGURE 16 ); anterior peristomial ring not exposed.................... 9

9(8) With dorsal lappets ( Fig. 21A View FIGURE 21 ); inferior thoracic chaetae type A ( Fig. 1E View FIGURE 1 ).................................................................................................. M. perkinsi Tovar-Hernández and Salazar-Vallejo, 2006

- Dorsal lappets absent ( Fig. 16A View FIGURE 16 ); inferior thoracic chaetae types B ( Fig. 1F View FIGURE 1 ) or C ( Fig. 1G View FIGURE 1 )......................... 10

10(9) With caruncle; interramal eyespots present in thorax and abdomen; inferior thoracic chaetae type B................... 11

- Caruncle absent; interramal eyespots absent; inferior thoracic chaetae type C..................................... 12

11(10) Dorsal collar margins rounded posteriorly, showing partially the anterior peristomial ring.................................................................................. M. carunculata Tovar-Hernández and Salazar-Vallejo, 2008

- Dorsal collar margins level, covering the anterior peristomial ring ( Fig. 16A View FIGURE 16 )................ M. lobiferum ( Ehlers, 1887)

12(10) Thoracic tori contacting ventral shields ( Fig. 19C View FIGURE 19 ); ventral sacs and dorsal pockets present ( Fig. 19B View FIGURE 19 )................................................................................................... M. pacifici ( Grube, 1859)

- Thoracic tori separated from ventral shields ( Figs 4B View FIGURE 4 , 14C View FIGURE 14 )................................................... 13

13(12) Radioles and anterior thorax with scattered dark spots ( Fig. 14C, E–F View FIGURE 14 ); ventral sacs absent....... M. heterops Perkins, 1984

- Radioles and anterior thorax without scattered dark spots; ventral sacs present ( Fig. 4D View FIGURE 4 ).. M. circumspectum ( Moore, 1923)

Kingdom

Animalia

Phylum

Arthropoda

Class

Insecta

Order

Coleoptera

Family

Carabidae