New insights into the morphology and evolution of the ventral pharynx and jaws in Histriobdellidae (Eunicida, Annelida)

Table 1 Comparison of main jaw features and jaw types in different families within the Eunicida

Family	Ref.	Mandibles	Maxillae					Type of jaws
Family	Ref.	Mandibles	Symmetry	Number of rows of dental plates	Presence of unidental forceps-like M1	Dorsal carriers	Ventral carriers	Type of jaws
Dorvilleidae	[6]	black, unmineralized, connected via ligament or two parts, ventral cutting plate present or absent	symmetrical	2–4	−/+	unpaired (single) carrier-like struсture	–	ctenognath
Eunicidae	[6, 14]	calcified partly fused shafts, ventral cutting plate present	asymmetrical	2	+	paired, broad and short	unpaired and delicate	eulabidognath
Hartmaniellidae	[6, 15]	black, not fused	subsymmetrical	2	–	paired, moderately long to short	–	symmetrognath
Histriobdellidae	this study	black, partly fused with long shafts, cutting plate present	symmetrical	2	–	unpaired, long (rod-like)	paired, short, sliding along mandibular shafts	ctenognath
Lumbrineridae	[6, 16]	lightly calcified, completely or partly fused, cutting plate present	symmetrical	2	−/+	paired, moderately long to short	–	symmetrognath
Oenonidae	[17]	black, unmineralized, connected via ligament, ventral cutting plate present	symmetrical plate number, plate size can vary between both sides	2	−/+	paired, long	unpaired, long, well sclerotized	prionognath
Onuphidae	[6]	calcified partly fused shafts, ventral cutting plate present	asymmetrical	2	+	paired, broad and short	unpaired and delicate	eulabidognath

ISSN: 2056-306X