Comparative Ecology of Bryozoan Radiations: origin of novelties in cyclostomes
Competition, clade replacement, and a history of cyclostome
and cheilostome bryozoan diversity.
Stenolaemates, including the cyclostomes
, form their skeletons almost entirely of low-Mg calcite; mineralogical complexity is provided by the gymnolaemate cheilostomes (Smith et al.
Among all extant forms of bryozoans, paleontological, morphological, and molecular phylogenetic evidence suggests that the ctenostome bryozoans are basal to both the cyclostome
and cheilostome grades (Taylor, 1990; Dick et al.
Lampreys are jawless vertebrates (agnathans) and the most primitive representatives of the cyclostome
branch from which it is feasible to obtain embryos routinely.
and cheilostome marine bryozoans, two clades with such attributes, have co-occurred in similar environments for 150 million years.
The lamprey, which is a cyclostome
, has spermatozoa that carry a spherical acrosomal vesicle at the anterior end of their heads, subacrosomal material between the acrosome and the nucleus, and a long perforatorium rod through the nucleus (Follenius, 1965; Stanley, 1967; Nicander and Sjoden, 1971; Jaana and Yamamoto, 1981) [ILLUSTRATION FOR FIGURE 6B OMITTED].
Recent research on the skeletal ultrastructure of cyclostome
bryozoans has revealed an unanticipated diversity of calcitic fabrics (e.
Vertebrata Craniata (First fascile: cyclostomes
The first volume of the series, published in 1948, covered lancelets, cyclostomes
, and sharks.
Contract notice for Pisitigude and cyclostomes
spread clarification 2016-2017.
Chemical zoology: deuterostomians, cyclostomes
, and fishes.