Vertebrates On The Brink As Indicators Of Biological Annihilation And The Sixth Mass Extinction


All vertebrate specimen data can be found on-line atARCTOS. Vertebrates began to evolve about 530 million years ago during the Cambrian explosion.

Origin of Free-Swimming VertebratesIn contrast to protochordates (hemichordates, urochordates, and cephalochordates), vertebrates are actively-feeding, predatory organisms that transfer by lateral undulation of an elongate physique. This group undergoes complete metamorphosis from a mobile larva to a sessile grownup, resorbing the tail and notochord. The few remaining species of tunicates belong to the taxa Thaliacea and Appendicularia (larvaceans).

5) The ultimate disposition of the animals must be described on Vertebrate Animal Form 5A. 3) The native or affiliated honest Scientific Review Committee must determine if a veterinarian’s certification of the research plan and animal husbandry plans is required.

Thaliaceans lack a tail and notochord; they don’t have any identified larval stage. They are small, free-swimming, pelagic barrel-shaped animals that use jet propulsion. Appendicularians don’t metamorphose, and are able to … Read More

Read More »