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The evolution of the irregular echinoid and of the sand dollar occurred in a very short time. The first irregular echinoid appears abruptly in the Early Jurassic (Sinemurian); and by the Toarcian, only ten million years later, irregular echinoids possess all the features necessary to permit them to live buried in the sediment. The first clypeasteroid appears in the Paleocene. By the middle Eocene its very specialized descendants, the sand dollars, have a worldwide distribution. This rapid evolution and diversification seem to result from a sudden adaptive breakthrough.

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A new trachyleberid ostracod genus, Schizoptocythere, is proposed for ten species from the early Tertiary of Saudi Arabia, Pakistan, and India. The genus is characterized by possessing strongly protruding eye-tubercles, which usually bear an extra tubercle or spine posteriorly. Nine species of the genus are described, including seven new species: Schizoptocythere circumspinosa, S. lissos, S. torquata, S. temperata, S. taurus, S. simopyge, and S. ventricosa.

• Read more about A new trachyleberid ostracod genus from the early Tertiary of western Asia

The Portlandian deposits of southern England contain a moderately abundant, low diversity bryozoan fauna. One new species, Microecia southwellensis, is described, and established species, apart from penetrant ctenostomes, are revised. The genus Elaphopora is considered invalid and E. cervina Lang is referred to Mesenteripora. The ecological niche usually occupied in the Jurassic by the cyclostome Stomatopora was filled by the earliest known cheilostome bryozoan, Pyriporopsis portlandensis Pohowsky, during most of Portlandian times.

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Nummulites obtusus (Sowerby) is redescribed and re-illustrated from the type area in India, and its morphology is discussed. Topotypes of N. perforatus (de Montfort) from Romania are also described and figured and the two species are shown to be distinct and to belong to different lineages. N. perforatus is restricted to the late Middle Eocene (Truncorotaloides rohri Zone) while N. obtusus occurs in the middle Middle Eocene (Globorotalia lehneri Zone).

• Read more about Two stratigraphically important Nummulites species from the Middle Eocene of India and Europe

Wolinella baltica gen. et sp. n. from the Arenig of Baltic province is the oldest known single-walled bryozoan. It is characterized by cylindrical zooecia, non-pseudoporous exterior wall, and well-developed communication canals between zooecia. Wolinella is a supposed ancestor of Corynotrypa, which occurs in the lowermost Llanvirn. Evolution from the latter genus to Dentalitrypa and to the boring ctenostome Ropalonaria originated in the Caradoc. The tendency to develop a common bud in Wolinella suggests that Diploclema also may be its descendant.

• Read more about Evolutionary relationships of the early Palaeozoic 'cyclostomatous' Bryozoa

Aristotle's lanterns of the Liassic echinoids Diademopsis tomesii (Wright) and Eodiadema aff. minutum (Buckman) are described, and compared with those of living echinoids. Diademopsis has a primitive lantern and weakly grooved teeth. The ultrastructure of these teeth is well preserved, and it is shown how Recent grooved, keeled, and diamond-shaped teeth could be derived from a tooth of this construction.

• Read more about Implications of lantern morphology for the phylogeny of post-Palaeozoic echinoids

Eocene crabs are described from the London Clay of Highgate and Sussex; the Elmore Formation, Brackelsham Group of Lee-on-the-Solent, Hampshire; the Barton Beds of Christchurch Bay and Alum Bay, Isle of Wight; and the Middle Headon Beds of Colwell Bay, Isle of Wight. Twenty species are represented, sixteen new, belonging to fifteen genera, one of them new. The new taxa are: Dromilites simplex sp. nov., D. lamarckii humerosus ssp. nov., Calappilia scopuli sp. nov., Bartethusa hepatica gen. et sp. nov., Typilobus belli sp. nov., T. obscurus sp. nov., Leiolambrus? longifrons sp.

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Among the preserved woody debris associated with the fossil conifer Pseudofrenetopsis parceramosa (Fontaine) Watson from a deposit in the Wealden of the Isle of Wight, three wood types have been characterized. One corticated twig with internal structure preserved, has provided good evidence that one of the woods belonged to Pseudofrenelopsis. This wood, which is of the Protopodocarpoxylon type, is represented by both mineralized and fusainized specimens and a comparison ofthese supports the view that the fusain was formed by charring.

• Read more about Anatomy and palaeoecology of Pseudofrenelopsis and associated conifers in the English Wealden

The study provides detailed quantitative analyses of faunal assemblages from various Upper Llanvirn shelly facies occurring with the Lower Ordovician successions of mid-Wales. In particular fifteen assemblages occur in about 90 m of varied sediments and bedded pyroclastics constituting the Ffairfach Group stratotype. The assemblages congregate into eleven distinct associations two of which recur five times. The lithological successions and taphonomic structure of the entombed assemblages indicate predominantly shallow-water, shoreface deposits dominated by benthos.

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The dalmanitacean trilobite genera Daytonia, Ommokris, Glyptambon, and Lygdozoon are described from the Silurian of North America. Daytonia and Ommokris are assigned to the Dalmanitinae; Glyptambon belongs to the Dalmanitidae but cannot be referred to an established subfamily; and Lygdozoon is assigned to the Synphoriinae, together with the genus Delops Rickards, 1965. Synphoriinids have previously been reported only from strata of Early and Middle Devonian age.

• Read more about Silurian dalmanitacean trilobites from North America and the origins of the Dalmanitinae and Synphoriinae