Silurian animals

Stromatoporoidea is an extinct clade of sea sponges common in the fossil record from the Middle Ordovician to the Late Devonian. They can be characterized by their densely layered calcite skeletons lacking spicules. Stromatoporoids were among the most abundant and important reef-builders of their time, living close together in flat biostromes or elevated bioherms on soft tropical carbonate platforms.

Pterygotidae (the name deriving from the type genus Pterygotus, meaning "winged one") is a family of eurypterids, an extinct group of aquatic arthropods. They were members of the superfamily Pterygotioidea. Pterygotids were the largest known arthropods to have ever lived with some members of the family, such as Jaekelopterus and Acutiramus, exceeding 2 metres (6.6 ft) in length. Their fossilized remains have been recovered in deposits ranging in age from 428 to 372 million years old (Late Silurian to Late Devonian).

thumb|Monograptus sp. from the Wenlock of Vailhan, Hérault, France. 12 cm block. Graptolites preserved in three dimensions.

Adelophthalmoidea (the name deriving from the type genus Adelophthalmus, meaning "no obvious eyes") is a superfamily of eurypterids, an extinct group of aquatic arthropods. Adelophthalmoidea is classified within the infraorder Diploperculata, in the suborder Eurypterina. The superfamily contains four families: Adelophthalmidae, Nanahughmilleriidae, Parahughmilleriidae, and Pittsfordipteridae.''''''

Pentamerida is an order of biconvex, impunctate shelled, articulate brachiopods that are found in marine sedimentary rocks that range from the Middle Cambrian through the Devonian.

Dibasterium is an extinct genus of euchelicerate, a group of chelicerate arthropods. Fossils of the single and type species, D. durgae, have been discovered in the Coalbrookdale Formation of the Middle Silurian period (Homerian age) in Herefordshire, England (in the United Kingdom). The name of the genus is derived from the Latin words dibamos ("on two legs") and mysterium ("mystery"), meaning "mystery on two legs" and referring to its prosomal (of the head) limbs. The species name durgae comes from Durga, a Hindu goddess with many arms.

Offacolus is an extinct genus of euchelicerate, a group of chelicerate arthropods. Its only species, O. kingi, has been found in deposits from the Silurian period (Homerian epoch) in the Wenlock Series Lagerstätte of Herefordshire, England. The genus is named after Offa, a king from the ancient kingdom of Mercia, and colus, a person who dwelled among (this time referring to) the Offa's Dyke. The species name honors Robert Joseph King, a British mineralogist who found the fossils of Offacolus.