abnormal male spongy urethra morphology abnormal navicular fossa morphology any structural anomaly of the dilated terminal portion of the male spongy urethra located in the glans penis right before the external urethral orifice, also referred to as the most distal pendulous urethra; it is lined by stratified squamous, non-keratinizing epithelium; during development, the glans of the penis is initially solid but cannulates to give rise to the navicular fossa abnormal navicular fossa of male urethra csmith abnormal fossa navicularis urethrae morphology MPheno.ontology 2012-11-30T03:32:00Z MP:0011838