part of part of in taxon develops from develops from has developmental contribution from has developmental contribution from has muscle origin has muscle origin has muscle insertion has muscle insertion composed primarily of Metatheria system skeletal muscle tissue muscle organ nipple mesoderm-derived structure gubernaculum (female) marsupium anterior iliac spine ilio-marsupialis muscle in pouchless marsupials provides mechanical support for the attached young [DOI:10.1046/j.1469-7580.2002.00087.x] A muscle that originates on the anterior iliac spine that passes through the inguinal canal before dividing into four branches, each attaching to a pouch nipple. ilio-marsupialis UBERON:0013715 In pouched marsupials, the ilio-marsupialis is less well developed, but may help in gland contraction to express milk during suckling (Griffiths & Slater, 1988) and it carries the genitofemoral nerve that innervates the mammary gland (Renfree, 1979) [DOI:10.1046/j.1469-7580.2002.00087.x] compressor mammae Associated with lumbar musculature. originally postulated to be involved in milk ejection, or for mammary support and for retraction of the teats. M. ilio-marsupialis M. compressor mammae