Info

1200 species

Class Cirripedia

1,000 (20)

True barnacles and small groups of parasitic taxa

Phylum Onychophora

70 (2)

Velvet worms; most confined to tropical habitats

Phylum Tardigrada

800 (17)

Water bears in aquatic and moist terrestrial habitats

^Estimates of species richness are for living taxa only, except for the subphylum Trilobitomorpha. The reliability of these estimates varies widely among taxa.

^Estimates of species richness are for living taxa only, except for the subphylum Trilobitomorpha. The reliability of these estimates varies widely among taxa.

FIGURE 1 Asaphiscus wheeleri, an extinct trilobite in the subphylum Trilobitomorpha. (Photograph courtesy of Sam M. Gon, III.)

proceeded gradually through a life with three larval stages, 14 or more juvenile steps in the first year of life, and multiple adult stages lasting a maximum of 3 more years.

0 0

Post a comment