The Late Cretaceous echinoid genus Micraster (irregular echinoids, Spatangoida) is one of the most famous examples of a continuous evolutionary lineage in invertebrate palaeontology. The influence of the environment on the phenotype, however, was not tested so far. This study analyses differences in phenotypical variations within three populations of Micraster (Gibbaster) brevis from the early ...

The present author has been studying the biochemical systematics of echinoids and asteroids of echinoderms by using some biochemical methods such as allozyme analysis, immunological assay, enzyme kinetic study, and comparison of amino acid composition (Matsuoka, 1980, 1986, 1987, 1992; Matsuoka et al., 1983; Matsuoka and Suzuki, 1989; Matsuoka and Hatanaka, 1991, etc.). Echinoderms are represen...

The community structure of Jamaican coral reefs has undergone drastic change since mass mortalities ofthe long-spined black sea urchin Diadema anrillarum Philippi occurred in 1983. In the absence of Diadema, algal abundance has increased enormously, up to a mean of 95% cover or 4.6 kg wet weight m-a. Coral cover, which was already low on some reefs following Hurricane Allen in 1980, has been fu...

The jaw apparatus of the regular echinoids is moved by a complex of muscles. Of these the largest and most accessible are the lantern retractor muscles which originate on the auricles and insert upon the pyramids which enclose the teeth. Preliminary experiments using Parechinus angulosus Mortensen showed that, while in this species these muscles could not be stimulated indirectly by way of elec...

Bindin plays a central role in sperm-egg attachment and fusion in sea urchins (echinoids). Previous studies determined the DNA sequence of bindin in two orders of the class Echinoidea, representing 10% of all echinoid species. We report sequences of mature bindin from five additional genera, representing four new orders, including the distantly related sand dollars, heart urchins, and pencil ur...

the echinoid fauna of basab area (aptian), northwest of kerman, is fairly rich and diverse, represented by pygaulidae, acropeltidae, emiratiidae, toxasteridae, holectypidae, stomechinidae and saleniidae. four regular echinoid species, among which three are new, assigned to genus tetragramma agassiz, are described and illustrated in the present paper. the new species are tetragramma basabensis, ...