Cossuridae Day, 1963

Zhadan, Anna, 2015, Cossuridae (Annelida: Polychaeta: Sedentaria) from Australian and Adjacent Waters: the First Faunistic Survey, Records of the Australian Museum 67 (1), pp. 1-24 : 3-4

Cossuridae Day, 1963

Key for species of Cossuridae of Australian and adjacent waters

1 Prostomium with anterior extension; very thick thoracic neuro-

chaetae, 9–11 thoracic chaetigers .............................................................. Cossura sp. cf. ginesi

—— Prostomium without anterior extension .................................................................................... 2

2 Abdominal segments with two short acicular chaetae per para-

podium ............................................................................................................ Cossura aciculata

—— Abdominal segments with capillary chaetae only ..................................................................... 3

3 Thoracic segments swollen, with dorsolateral glandular pads;

prostomium obtuse, round ......................................................................................................... 4

—— Thoracic segments not swollen, prostomium conical, round or trapezium-shaped ....................................................................................................................... 5

4 Anterior margins of the segmental borders dorsally are drawn

forward, toward the base of branchial filament; prostomium with

round or almost straight anterior margin, very thick thoracic

neurochaetae ...................................................................................... Cossura hutchingsae n.sp.

—— Anterior margins of the segmental borders dorsally perpen-

dicular to body axis; prostomium round. Big worms, body

thick, cylindrical, 28+ thoracic chaetigers, thoracic neurochaetae

thicker than notochaetae ....................................................................................... Cossura sp. A

5 Prostomium rectangular or trapezium-shaped, with round or almost straight anterior margin, 22–26 thoracic chaetigers ...................... Cossura keablei n.sp. —— Prostomium conical, with pointed or round tip; 13–22 thoracic chaetigers ................................................................................................................................... 6

6 Thoracic neurochaetae notably thicker than notochaetae;

prostomium with pointed tip, pygidium with 3 anal cirri but

without intercirral processes ........................................................... Cossura sp. cf. longocirrata

—— Thoracic neurochaetae have almost the same width as notochaetae .............................................. 7

7 Pygidium with 3 anal cirri and interracial processes, prostomium with pointed tip; branchial filament arising from posterior part of chaetiger 2 ............................................................................... Cossura sp. cf. pygodactylata

—— Pygidium with 3 anal cirri but without intercirral processes,

prostomium with round tip; branchial filament attached to

segmental border between chaetigers 2 and 3 ........................................................................... 8

8 17–20 thoracic chaetigers, thoracic width 250–300 μm ............. Cossura queenslandensis n.sp. —— 21–32 thoracic chaetigers, thoracic width 300–660 μm ................................ Cossura consimilis

Species descriptions