Sea-urchins Sentence Examples
Klein (1734) to denote the tests of the Echini or sea-urchins; its later use for the animals themselves, or for the whole phylum, was an error in both history and etymology.
Those plates are perhaps constant throughout sea-urchins and starfish (though it would puzzle any one to detect them in certain Silurian echinoids), and they may be traced in some of the fixed echinoderms; but there is no proof that they represent the radials of a simple crinoid, and there are certainly many cystids in which no such plates existed.
They do not feed on fish, like true otters, but on clams, mussels, sea-urchins and crabs; and the female brings forth but a single young one at a time, apparently at any season of the year.
We are currently investigating crystal growth in a number of natural systems including coccoliths and sea urchins.
Other fossils include the sea urchins (echinoids ), which occur in a number of varieties.Advertisement
Lime is, in fact, absorbed to an enormous extent by fishes, molluscs, crustacea, calcareous algae and sponges, starfishes, sea-urchins and feather stars, many polyzoa and a multitude of protozoa (mainly the foraminifera).
The Tornaria larva offers a certain similarity to larvae of Echinoderms (sea-urchins, star-fishes, and sea-cucumbers), and when first discovered was so described.
North of the Atlas it belongs to the European type, in the south it contains a fauna of oysters and sea-urchins belonging to the facies " africano-syrian " of Zittel.
Corals, both reef-builders and others, flourished in the clearer waters; rugose forms are represented by Amplexoid, Zaphrentid and Cyathophyllid types, and by Lithostrotion and Phillipsastraea; common tabulate forms are Chaetetes, Chladochonus, Michelinia, &c. Amongst the echinoderms crinoids were the most numerous individually, dense submarine thickets of the long-stemmed kinds appear to have flourished in many places where their remains consolidated into thick beds of rock; prominent genera are Cyathocrinus, Woodocrinus, Actinocrinus; sea-urchins, Archaeocidaris, Palaeechinus, &c., were present; while the curious extinct Blastoids, which included the groups of Pentremitidae and Codasteridae, attained their maximum development.
There was also sufficient comprehension of the differences between the main classes of Echinoderms - the sea-urchins or Echinoidea, the starfish or Asteroidea, the brittle-stars and their allies known as Ophiuroidea, the worm-like Holothurians, the feather-stars and sea-lilies called Crinoidea, with their extinct relatives the sac-like Cystidea, the bud-formed Blastoidea, and the flattened Edrioasteroideawhile within the larger of these classes, such as Echinoidea and Crinoidea, fair working classifications had been established.Advertisement
In other parts the rocks were totally bare from having been grazed by massive numbers of spiny sea urchins.
Underwater you'll find plenty of anemones, Ross corals and edible sea urchins.
Marine life is made up of crustaceans, echinoderms, spiny black sea urchins and a resident school of spotted sweetlips.
In coastal areas there can also be painful results from standing on sea urchins or contact with the spines of certain fish.
Crinoids are sometimes called sea lilies, but are in fact creatures related to starfish and sea urchins.Advertisement
Other fossils include the sea urchins (echinoids), which occur in a number of varieties.
Sometimes sea urchins may be occupying your seashell find.
For example, when studying sea creatures it will be more interesting to visit a marine museum and science center to play in a touch-tank than to see pictures of starfish, sea urchins and hermit crabs.