usually inhabit dark and moist microhabitats, chiefly in forest litter, stones, moss, rotten logs, soil crevices, ant or termite tunnels, and less frequently, bromeliads (Picado, 1911; Carvalho, 1941; Monge-Najera, 1995; Grimaldi and Engel, 2005).
In contrast to arthropods, onychophorans
do not have segmented limbs, as is also the case with their presumed common fossil ancestors, says Georg Mayer.
Characterisation and localisation of the opsin protein repertoire in the brain and retinas of a spider and an onychophoran
. BMC Evol.
are almost all carnivores that prey on small invertebrates such as snails, isopods, earth worms, termites, and other small insects (Hamer et al.
To make the onychophoran
connection, Ramskold and Hou have stretched the boundaries of the phylum.
The first described onychophorans
from Costa Rica were collected in the Nineteenth Century around San Jose, capital of the country, by the Alsacian naturalist Paul Biolley.
are predators that hunt for small invertebrate prey that they capture with an adhesive net mainly composed of water and protein (Bouvier 1905, Read & Hughes 1987, Mora et al.
Arthropod phylogeny: onychophoran
brain organization suggests an archaic relationship with a chelicerate stem lineage.
have a cylindrical and unsegmented body, with a pair of antennae on its anterior end, one eye at the base of each antenna, and a ventraly located mouth with a well-developed jaw, which represents a modification of the anterior region of the body.
This paper complements Monge-Najera and Hou's (2000) paleoecological study by reporting on experimental decay of these rare animals and presents computer-aided photorealistic reconstructions of extinct onychophorans
For almost a century authors have disagreed about their taxonomic position, although recent studies have supported the hypothesis that they were early ancestors of onychophorans
(Hou and Bergstrom 1995, Monge-Najera 1995).
This paper revisits the controversy (with emphasis in onychophorans
, which include emblematic organisms such as Hallucigenia), presents new data about the Chengjiang (Cambrian of China) faunal community and compares it and the Burgess Shale (Cambrian of Canada) with on ecologically similar but modern tropical marine site where onychophorans
are absent, and with a modern neotropical terrestrial onychophoran