Practice question

Priapulidan life history involves indirect development where fertilized egg hatches into lorica larva encased in protective cuticular lorica composed of longitudinal plates including dorsal and ventral shields forming tubular armor resembling loriciferan lorica. Larva possesses spinose introvert and functional gut, moulting through several successive loricate stages before transforming into vermiform adult. Lorica offers protection in interstitial meiobenthic sediments from predation and abrasion. Presence underscores phylogenetic affinity among loricate Scalidophora and illustrates conservative larval morphology and ecdysis-driven growth pattern in early Cambrian-derived lineage adapted to soft sediments globally distributed in colder oceans.