Gastrulation occurs in multiple phases at two distinct sites in Latrodectus and Cheiracanthium spiders

Table 1 Evaluation of cell internalization traits across spider phylogeny

Sub order	Genus	Source	Trait
Sub order	Genus	Source	Ingression of single cells before blastopore forms	Cumulus forms before Primitive Plate	Internalization at germ disc rim or extra-blastoporal site	Late internalization at caudal structure
Models	*Canonical model*	[11, 12]	No	No	No	No
Models	*Working model*	This paper	No	*Yes*	*Yes*	No
*Mesothelae*	Heptathela	[33]	Yes	No cumulus?	*Yes*	No
*Mygalomorphae*	Atypus	[34]	Yes	No	No	No
	Ischnothele	[12]	Yes	No	No	Pit present ^a
	Ischnocolus	[35]	Yes	No	No	No
*Araneomorphae*	Agelena	[12, 13]	No	No	No	Pit present ^a
	Torania	[25]	Yes	No	No	No
	Cupiennius	[21]	No	No	No	No
	Cheiracanthium	This paper	No	*Yes*	*Yes*	No
	Latrodectus	This paper	No	*Yes*	*Yes*	No
	Parasteatoda	[17, 29]	No	No	*Yes*	Pit present ^a
	Zygiella	[26]	No	*Yes*	No	Yes

Bold italic terms indicate agreement with our model
Italic terms indicate agreement with canonical model but data are not incorporated into our model
Plain text terms indicate agreement with canonical model
^aPresence of a pit suggests cell internalization, but direct evidence (cell tracing, histology) does not exist

ISSN: 2041-9139