A study of the Upper Ordovician trepostomate bryozoans belonging to the families Amplexoporidae and Monticuliporidae, from the eastern Anti-Atlas of Morocco, is presented here. They occur in the marly to fine-grained limestone, intermediate unit of the Khabt-el-Hajar Formation, late Katian in age, representing outer-ramp depositional environments. They inhabited the highest paleolatitude known for a bryozoan fauna during the Ordovician, estimated at more than 65–70°S. A total of 11 species of the genera Anaphragma, Atactoporella, Homotrypa, Monotrypa, Monticulipora, and Prasopora are described. Three species are already known from the equatorial-tropical paleocontinents of Baltica, Laurentia, and Siberia: Anaphragma mirabile, Monotrypa jewensis, and Prasopora falesi. Four new taxa are described:Anaphragma undulata, Atactoporella moroccoensis, Monticulipora globulata, and Monticulipora irregularis.

The two species of Anaphragma and the one of Atactoporella display significantly larger zoarial sizes than congeneric species, representing gigantism among bryozoans. Polar gigantism is rejected for the two species of Anaphragma as is gigantism related to photosynthetic endosymbionts. An alternative proposal for their giant size is their long zoarial life span due to their well-balanced, robust branching form, with a relatively wide basal supporting surface, adapted to unconsolidated substrates in environments below wave base. Their great stability in outer-ramp environments, with infrequent storms, would allow the zoaria to grow for an extended time and reach large sizes before being overturned and buried. Atactoporella moroccoensis, has both zoaria and zooecia gigantic, suggesting a hypothesis of polar gigantism.

The Wenlock (middle Silurian) Eramosa Lagerstätte of the Bruce Peninsula, Ontario, Canada, is becoming known for its rich and diverse faunas, different preservational styles, and a combination of soft-body preservation associated with shelly body and trace fossils. Sampling for scolecodonts—the jaws of polychaete annelids—has yielded unique material. Hindenites parkheadensis new species is described from abundant specimens, including apparatuses, from a monospecific fauna that has allowed the complete dorsal maxillary apparatus to be reconstructed. The new species was recovered by acid digestion of carbonates, which are interpreted as having been deposited in shallow, marginally marine environments; the species may become a useful paleoenvironmental indicator, and the occurrence of Hindenites at Park Head, Ontario, is the first record of the genus outside of Baltoscandia. Bedding-plane material from Wiarton, Ontario, reveals a more diverse fauna of seven to nine additional polychaete taxa, most belonging to Kettnerites and Oenonites. Strata at Wiarton are interpreted as having been deposited in environments with good water circulation and open-marine conditions. The faunal composition of Eramosa polychaetes varied between localities of the Lagerstätte outcrop belt, supporting previous interpretations of differences in environment and/or taphonomic history. The relative abundance of scolecodonts suggests that jaw-bearing polychaetes played a significant role in the biotas that are now preserved in the Eramosa Lagerstätte. Moreover, the results underpin the notion that different polychaete species had variable environmental preferences and tolerances during the Silurian, and that polychaetaspids and paulinitids formed two of the most common and widely distributed families.

Oaks and their associated gallwasps are often cited as a classic example of coevolution in a plant-insect system. Therefore, it is expected that these gallwasps should demonstrate a high degree of host fidelity over their evolutionary history. To test this, we studied 25 fossil floras from the Oligocene through Pliocene of the western United States. Galls were found on the leaves of Quercus simulata-type Knowlton, 1898 and Q. pollardiana-type (Knowlton) Axelrod, 1940, and match previously reported galls of the form genus Antronoides Waggoner and Poteet, 1996. These fossil leaf-galls are similar to those made on oaks by modern Cynipini wasps, and were restricted to two oak species. Galls are present on these oaks in western floras for a span of 30 million years, indicative of remarkable host fidelity through time. The distribution of galled leaves from across the western United States indicates that the radiation of this group of gallwasps occurred more or less simultaneously across a wide geographic area.

A new echinoderm fauna is reported from the Brassfield Formation (Rhuddanian, Silurian) of Bath County, Kentucky. The Brassfield Formation was the first extensive marine unit to be deposited following the end-Ordovician glaciation and extinctions and represents several shallow, open-marine facies. These facies supported a diverse pelmatozoan fauna. This report not only extends the geographic distribution of this fauna, but also the temporal range of the fauna back to Rhuddanian time. Six pelmatozoans are reported, including the crinoids Browerocrinus arthrikos n. gen. n. sp., Temnocrinus americanus n. sp., Stereoaster sp., and Dendrocrinus sp.; and the glyptocystitids Brockocystis nodosarius Foerste, 1919, and Anartiocystis whitei Sumrall, 2002. In addition, the asteroid Gordonaster brassfieldensis Blake and Ettensohn, 2009, was reported previously from this locality. Browerocrinus increases the diverse calceocrinid fauna from the Brassfield Formation; Temnocrinus was previously only known from the Homerian (Silurian) of England; and this is the first known occurrence of Stereoaster beyond the greater Dayton, Ohio, region. Furthermore, this is the first Brassfield locality known with two glyptocystitid taxa.

A new species of aphroditiform polychaete, Protopholoe colombiana, is described from the Coniacian of Colombia, South America, increasing the number of species of this genus known from the fossil record to two. This is the first occurrence of fossil soft-bodied polychaetes in the Tropical Americas, and indicates that aphroditiforms were spread worldwide during the Mesozoic.

A Silurian (Llandovery, Aeronian) Lagerstätte in Kalana, Estonia, has revealed exceptionally preserved noncalcified thalli of dasycladalean (divison Chlorophyta) algal fossils. The siphonous, serially segmented fossils of Palaeocymopolia silurica n. sp. are closely similar to P. nunavutensis, a Ludlovian species from the Arctic Canada. The occurrence of closely related species at Baltica and Laurentia paleocontinents indicates a wide distribution of noncalcified algal flora on both sides of the Iapetus Ocean in the Paleozoic. The exceptionally well-preserved specimens from the Kalana Lagerstätte show similarity to extant species Cymopolia barbata, with lack of a calcium carbonate skeleton being the major observable difference from the latter.

A newly discovered Verbeekina assemblage from the Xiaoxinzhai Section in the Baoshan Block in western Yunnan, China, provides additional data for better understanding fusulinid biostratigraphy and the thermal condition of middle Permian (Guadalupian) seawater of this block. This assemblage comprises 11 species of six genera, including Verbeekina, Pseudodoliolina, Sumatrina, Yangchienia, Xiaoxinzhaiella, and ?Rugosochusenella. The age of this assemblage is considered to be Midian (approximately Capitanian), based on combined evidence of stratigraphic position and specific composition. Furthermore, this assemblage bears two unusual attributes: overwhelming dominance of Verbeekina and relatively low total diversity, compared with coeval fusulinids from South China, which represents a paleo-tropical setting during the middle Permian. These features indicate that the Baoshan Block was probably located in a subtropical setting with warm water during the Midian time; however, its water temperature was still not as optimal as the tropical area (e.g., South China) for the diversification of fusulinids.

New Ediacaran fossil finds at Sekwi Brook occur in lower shoreface to offshore transition beds at the top of the Blueflower Formation, which are the most shallow-water facies and the youngest strata in which Ediacara-type fossils have been described from the Mackenzie Mountains of NW Canada. Newly discovered Ediacaran body fossils include two new tubular genera: Sekwitubulus annulatus new genus new species was a mm-diameter rigid annulated tube that was rooted to the sea bottom by a holdfast; Annulatubus flexuosus n. gen. n. sp. was a cm-diameter, flexible annulated tube. In conjunction with previously described large attachment discs representing the form-genus Aspidella and a single specimen of the dickinsonid Windermeria, these fossils define an assemblage that differs markedly from the rangeomorph-dominated deeper-water and older assemblages lower in the same section at Sekwi Brook. In contrast, trace fossils show little change upwards through the Blueflower Formation, at least in part reflecting their origin by microbial grazers on mats that formed during low-energy periods in both deep- and shallow-water environments. This implies that the stratigraphic succession of Ediacaran fossils in NW Canada and probably globally represents both evolutionary changes with age and the paleoecology of specific depositional settings.

Bryozoans and all biomineralized metazoan phyla extend back into the Cambrian. Pywackia Landing, 2010 is confirmed as a secondarily phosphatized, late Cambrian stenolaemate bryozoan with colonial habit; mineralized zooarium (originally calcareous); granular/rarely granular-prismatic histology of its trilamellar walls; and polymorphism shown by deep autozooecia with diaphragms and hemiphragms, axial zooecia with diaphragms, and probable nanozooecia. The irregular form of Pywackia reflects growth as a 14-hedron that could not branch and a lack of structures such as thickened walls or styles that maintain regular autozooecial spacing in later stenolaemates. Pywackia is a stem group stenolaemate with a stolon modified into a budding axial zooid and autozooid budding. It is morphologically simpler than the highly evolved late Tremadocian bryozoans of South China with features such as styles, cystiphragms, thickened zooecial walls, and massive or branching colonies. As with some bryozoans, Pywackia lacks holdfasts but has lineated living chambers and variably sized autozooecia. The late Cambrian origin of bryozoans, euconodonts, polyplacophorans, and cephalopods set the stage for the Ordovician Radiation's complex communities. Pywackia is not a pennatulacean octocoral. It lacks both a pennatulacean axial rod histology and a budding zooid that remains confluent with daughter autozooids. Indeed, Pywackia walled off its axial zooid. Similarity of the 6- and 12-sided Pywackia zooarium with circular to 4-sided pennatulacean axes only includes calcareous composition and the general shapes of Pywackia zooaria and some Lituaria axial rods. The pennatulacean record does not extend from the Mesozoic into the Cambrian, and early cnidarians were not phosphatic. The diagnosis of Pywackia is modified.

Newly discovered mandibles and lower dentition of the middle Eocene rodent Thisbemys brevicrista from the Green River Basin, Wyoming, are the basis for a species re-diagnosis. Previously, only the upper dentition and a partial maxilla of T. brevicrista were known from Br3. New specimens from Br2 now include the lower molars, additional upper molars, and maxillary fragments including a partial zygomatic arch that preserves the relationship of the arch to the first upper molar. In addition, the presence of T. brevicrista at Br2 documents the co-existence of T. brevicrista with T. perditus, T. nini, T. plicatus, and T. corrugatus. Formerly, the latter two species were differentiated primarily using stratigraphy. Now, morphology and size can also be used. Thisbemys brevicrista is intermediate in size between T. plicatus and T. corrugatus, and can readily be distinguished from these species based on unique features of the upper and lower molars, which include an additional loph on the two anterior upper molars and a complete metalophid on m1–3. The original type specimen of T. brevicrista appears to be lost, thus a neotype is designated as part of the re-diagnosis. Discovery and description of the lower dentition and mandibles of T. brevicrista clarifies the alpha taxonomy of this species, and increases its utility for studies of phylogenetic relationships and for documenting Eocene mammalian diversity patterns.

Trochotomidae is a small but distinctive extinct family of pleurotomarioidean gastropods characterized by trochiform shells with an elliptical trema. Two new species of trochotomids are described from Pliensbachian deposits in the Neuquén Basin, Argentina. The new genus-group name Placotoma is proposed to replace the pre-occupied name Discotoma Haber non Mulsant. The record of Trochotoma (Trochotoma) protonotialis new species and Trochotoma (Placotoma) neuquensis new species in the early Jurassic of Argentina extends the paleobiogeographical distribution of the genus (and the family) to the Southern Hemisphere. The new taxa reported here represent a component of the pleurotomarioidean adaptive radiation that took place in the Tethyan region during the earliest Jurassic. They are related to local patch coral reefs of shallow, open-marine paleoenvironments, agreeing with the known habitat of most species of this family. The group was well represented in the Tethyan region during the Mesozoic, especially during the Jurassic, and the new species represent its southernmost occurrence.

The new edrioasterine Pseudedriophus guensburgi n. gen. n. sp., is described from the Lower Ordovician Ninemile Shale of central Nevada based on three complete to partial small specimens, a well-preserved large ambulacrum, and an isolated ambulacral floor plate. The weathered-out holotype of this edrioasterine exposes the bottom surface of the theca that bears an aboral collar, peduncular stalk, and attachment disk, features that are poorly known in this clade. These specimens were found with a single specimen of a new edrioblastoid, Porosublastus inexpectus n. gen. n. sp., only the second edrioblastoid ever found in the Early Ordovician. Some of the ambulacral cover plates are stripped off one of the ambulacal grooves, revealing new information about how the ambulacra are built in this rare group of bud-shaped edrioasteroids.

An unusual, new, giant edrioasteroid Bizarroglobus medusae n. gen. n. sp. is described from the Middle Ordovician Kanosh Shale of west-central Utah. This species has a pattern of ambulacral branching with side ambulacra arising alternately from a main ambulacral trunk, previously undocumented in edrioasteroids. This pattern is interpreted as a strategy for allometrically increasing the feeding surface during ontogeny. Bizarroglobus further differs from other isorophid edrioasteroids in the plating of the peripheral rim, and the presence of pores in the interambulacral plates primarily along the edges of the ambulacra.

The proboscidean Gomphotherium is reported here from the Alajuela Formation of Panama. Gomphotherium was widespread throughout Holarctica during the Miocene, and the Panama fossil represents the extreme southernmost occurrence of this genus in the New World. Allocation of the Panama Gomphotherium to a valid species is impossible given both the fragmentary material represented and the taxonomic complexity of species assigned to this genus. In North America, Gomphotherium has a relatively long biochronological range from the middle Miocene (∼15 Ma) to early Pliocene (∼5 Ma). Based on morphological comparisons, the Panama Gomphotherium is either middle Miocene, thus representing the earliest-known entry of this genus into Central America, or late Miocene/early Pliocene, which challenges the currently accepted middle Miocene age of the Alajuela Formation as it has been previously reported from Panama.

A new eocrinoid ?Ubaghsicystis sp. from the middle Cambrian (Series 3, Stage 5) Burgess Shale is reported based on a single known specimen. This species extends the stratigraphic range of columnal-bearing eocrinoids in Laurentia significantly from Cambrian Stage 7 (Guzhangian) to Stage 5. It increases the diversity of echinoderms in this well-known fossil-Lagerstätte, provides the oldest evidence of columnal-bearing eocrinoids from Laurentia, and further documents the cosmopolitan distribution of middle Cambrian echinoderm clades.