This study reports the earliest known reef-building anthaspidellid sponge, Rankenella zhangxianensis n. sp., from the Cambrian Series 3 (late Stage 5–early Guzhangian) deposit of the Zhangxia Formation, Shandong Province, China. Rankenella zhangxianensis mostly occurs within Epiphyton-Rankenella-Cambroctoconus reefs, with minor occurrence from inter-reef grainstone. The species has anthaspidellid-type regular ladderlike spicule networks consisting of dendroclones and trabs, and is characterized by trabs parallel/subparallel to the gastral surface that diverge and meet the dermal surface, which is typical of the genus. Compared to R. mors and R. hamdii, reported from the late Cambrian Series 2–late Cambrian Series 3 of Australia and the late Cambrian Series 3–early Furongian of Iran, respectively, R. zhangxianensis is characterized by a relatively thicker wall, high angle (~90°) between dermal surfaces and intersecting trabs, and minor occurrence of differentiated canals. On the other hand, R. zhangxianensis mainly shows obconical shape, which is far less diverse than the other two species showing conicocylindrical, digitate, explanate, or bowl shapes. These Cambrian Series 3 reefs from China are the ancestors of the Furongian anthaspidellid-microbial reefs and the Early Ordovician anthaspidellid-microbial reefs that flourished worldwide. They represent the resurgence of reef-building metazoans after the extinction of archaeocyaths at the end of Cambrian Series 2.

Cambrian biostratigraphy of the Indian subcontinent is best documented from the Parahio Formation of the Tethyan Himalaya. Recently established trilobite biostratigraphy shows that the formation encompasses the latest part of unnamed Stage 4 and much of unnamed Stage 5. A variety of small shelly fossils have been recovered via acid digestion of carbonate beds and include tetract and pentact hexactinellid sponge spicules, chancelloriid spicules belonging to Chancelloria sp. and a new species, Archiasterella dhiraji, shells of an helcionelloid comparable to Igorella maidipingensis, a meraspid ptychopariid trilobite, the tubular Cupitheca sp., a poorly preserved hyolith, and an assortment of spinose microfossils of uncertain affinity. These newly recovered microfossils are consistent with the trilobite-based lower and middle Cambrian age determination and do not support a late Cambrian age for the top of the Parahio Formation advocated in some recent literature. The microfossils reported herein significantly expand the known diversity of such fossils from Cambrian strata in the Himalayan region, and allow for comparison of this fauna with others from Gondwanaland and elsewhere. Integration with trilobite data indicate that the stratigraphic ranges of many small shelly fossils described in this study are greater than previously recognized.

The isolation of Zealandia in the latest Cretaceous and early Paleogene following the final break-up of Gondwana fostered significant provincialism in molluscan faunas, concomitant with the segmentation of oceanic circulation patterns and changing climate nearing the end of the greenhouse phase in the Southwest Pacific. The earliest volutes (Gastropoda: Volutidae) from the Zealandian region reflect this isolation after separation from the Marie Byrd Land region of West Antarctica with several endemic groups being recognized for the first time since collecting first started in the Wangaloa Formation at Mitchells Rocks (Wangaloa), South Island, New Zealand in 1869. Five taxa attributed to the Volutidae are described herein from South Island (Wangaloa Formation and Steel Greensand) and also the Chatham Islands (Red Bluff Tuff) from the early (mid-Danian) to late Paleocene (Thanetian?). These comprise a new mid-Danian fulgorariine? genus and species, Wangaluta henaconstricta n. gen. n. sp.; a new combination also from the Wangaloa Formation, Wangaluta? neozelanica (Finlay and Marwick, 1937); two new zidonine volutes, the mid-Danian Alcithoe. s.l. wangaloaensis n. sp. from the Wangaloa Formation, and also Teremelon onoua n. sp. from the late Paleocene-early Eocene of the Red Bluff Tuff; and a probable volute, Fulgorariine? gen. indet. sp. indet. from the mid-Danian of the Steel Greensand. All of these taxa are endemic in the early Paleogene of New Zealand and represent a significant boost in our knowledge of post-K-Pg boundary diversification of volutid gastropods in the shrinking Weddellian Biotic Province in the southern rim of the Pacific.

The early Albian to mid-Albian cosmopolitan genus Douvilleiceras is represented in the Haida Gwaii archipelago of western British Columbia by five species, D. mammillatum (Schlotheim), D. offarcinatum (White), D. scabrosum Casey, D. spiniferum (Whiteaves), and D. aff. spiniferum (Whiteaves). Specimens of one of these taxa, D. spiniferum, are particularly abundant on Haida Gwaii and the species is discussed with respect to its morphological variability and ontogenetic development. The important morphological features for taxonomic criteria of the genus Douvilleiceras are the mode of tuberculation, the pattern of ribbing, and the proportions of the shell in the middle growth stage.

Study of type and new material of the pterygometopine Achatella Delo, 1935 demonstrates the presence of four species in Upper Ordovician (Katian) strata of Laurentian North America, A. achates (Billings, 1860) from the northeastern United States and the St. Lawrence lowlands of Canada, A. carleyi (Meek, 1872) from the Cincinnati region, Ohio and Kentucky, A. katharina (Bradley, 1930), from Missouri and Oklahoma, and A. clivosa Lespérance and Weissenberger, 1998 from the Gaspé Peninsula, Quebec. Perhaps as many as five additional species are present in Sandbian–Katian strata of the Laurentian terranes of Scotland and Northern Ireland, although only three of these are known well enough to code for phylogenetic analysis. The oldest pterygometopines, including species of Achatella, are known from Middle Ordovician strata of Baltica. Phylogenetic analysis supports a single migration event from Baltica from Laurentia, followed by a modest diversification in the latter region.

Lower Silurian conodonts were recovered from carbonate beds in the upper Zalaa and lower Sharchuluut formations at Yamaan Us in the Shine Jinst region, Gobi-Altai Zone, of southwestern Mongolia. Conodonts are described from the Zalaa Formation for the first time; key taxa recovered include Distomodus kentuckyensis Branson and Branson, 1947, Ozarkodina hassi (Pollock, Rexroad, and Nicoll, 1970), Pranognathus siluricus (Pollock, Rexroad, and Nicoll, 1970), and Pseudolonchodina expansa (Armstrong, 1990). These species constrain the onset of the Silurian carbonate platform, upper Zalaa to lower Sharchuluut formations, to the Pranognathus tenuis Zone, middle Aeronian. The presence of a cosmopolitan conodont fauna places these strata from the Gobi-Altai Zone in a basin-shelf marine setting with connection and circulation to the open ocean during the Llandovery.

We report three isolated humeri of small-sized parareptiles, which represent two different taxa, from the lower Keuper (Erfurt Formation) of Germany. They constitute the first definitive evidence of parareptiles in the lower Keuper. The specimens represent the first records of an owenettid procolophonian (aff. Barasaurus) from Europe and of a putative gracile-built procolophonid. This indicates the coexistence in the Middle Triassic of Germany of two procolophonian lineages that first appeared in the fossil record in the late Permian and survived the Permian–Triassic extinction. Although based on isolated limb bones, they highlight the taxonomic diversity of the still poorly known tetrapod assemblage of the lower Keuper in southwestern Germany.

Sauropod dinosaurs are rare in the Cretaceous North American fossil record in general and are absent from that record for most of the Late Cretaceous. Sonorasaurus thompsoni from the Turney Ranch Formation of the Bisbee Group of Arizona, USA, potentially represents one of the youngest sauropods before their ca. 30-million-year-long hiatus from the record. The anatomy of Sonorasaurus has only been briefly described, its taxonomic validity has been questioned, several hypotheses have been proposed regarding its phylogenetic relationships, and its life history, geologic age, and reported paleoenvironment are ambiguous.

Herein we assess the systematics, paleoenvironment, life history, and geologic age of Sonorasaurus based on firsthand observation, bone histology, and fieldwork in the holotypic quarry and environs. The validity of S. thompsoni is substantiated by autapomorphies. Cladistic analysis firmly places it within the Brachiosauridae, in contrast to results of some recent analyses. Bone histology suggests that the only known exemplar of Sonorasaurus grew slowly and sporadically compared to other sauropods and was approaching its adult size. In contrast with previous assessments of a coastal/estuarine paleoenvironment for the Turney Ranch Formation, our sedimentological and plant macrofossil data indicate that Sonorasaurus lived in a semiarid, low relief evergreen woodland that received highly variable (perhaps seasonal) precipitation. We obtained detrital zircons from the holotypic quarry for U-Pb dating, which only yielded Barremian-aged and older grains, whereas other radiometric and biostratigraphic data suggest that the sediments at the quarry were deposited near the Albian-Cenomanian boundary.

Sonorasaurus is taxonomically valid, represents one of the geologically youngest brachiosaurid sauropods, and inhabited a harsh inland evergreen-dominated woodland environment that limited its growth. A review of other Bisbee Group dinosaurs suggests that its fauna, although poorly sampled, exhibits broad similarity to those from coeval North American horizons, reinforcing the apparent faunal homogeneity at the time.

The Careless Creek Quarry (CCQ) is a multitaxic bonebed in the Campanian Judith River Formation of south-central Montana (USA) that produced a diverse assemblage of vertebrates, including several dinosaurian clades. We describe the morphology of the CCQ hadrosaurid material and reevaluate its taxonomic affinities. Our osteological comparative observations, coupled with maximum parsimony phylogenetic analyses, indicate that the majority of the hadrosaurid material is referable to kritosaurin saurolophines. Only an ischium is unambiguously referable to Lambeosaurinae. Most of the kritosaurin specimens likely represent a taxon that forms a polytomy with species of Gryposaurus and Rhinorex condrupus Gates and Sheetz, 2015. This form may represent individuals of either G. latidens Horner, 1992 or G. notabilis Lambe, 1914, or a new species cogeneric or not with Gryposaurus. The juvenile material exemplifies several patterns of mandibular and appendicular osteological variation previously observed in other hadrosaurids. However, it also shows some departures from the common trends, supporting the fact that not all skeletal growth changes can be generalized to all hadrosaurids.

Heavily tuberculated glyptosaur osteoderms were collected in an active limestone quarry in northern Berkeley County, South Carolina. The osteoderms are part of a highly diverse late Paleocene vertebrate assemblage that consists of marine, terrestrial, fluvial, and/or brackish water taxa, including chondrichthyan and osteichthyan fish, turtles (chelonioid, trionychid, pelomedusid, emydid), crocodilians, palaeopheid snakes, and a mammal. Calcareous nannofossils indicate that the fossiliferous deposit accumulated within subzone NP9a of the Thanetian Stage (late Paleocene, upper part of Clarkforkian North American Land Mammal Age [NALMA]) and is therefore temporally equivalent to the Chicora Member of the Williamsburg Formation. The composition of the paleofauna indicates that the fossiliferous deposit accumulated in a marginal marine setting that was influenced by fluvial processes (estuarine or deltaic).

The discovery of South Carolina osteoderms is significant because they expand the late Paleocene geographic range of glyptosaurines eastward from the US midcontinent to the Atlantic Coastal Plain and provide one of the few North American records of these lizards inhabiting coastal habitats. This discovery also brings to light a possibility that post-Paleocene expansion of this group into Europe occurred via northeastward migration along the Atlantic coast of North America.

The holotype partial skull of Agorophius pygmaeus (the monotypic form for both the genus Agorophius and the Family Agorophiidae) has been missing for approximately 140 years. Since the discovery of Agorophius pygmaeus, many additional taxa and specimens have been placed in the Family Agorophiidae, only to be reclassified and removed later. This has created confusion as to what is and what is not an agorophiid and a lack of clarity as to what characteristics delimit the Agorophiidae. A newly discovered skull of an agorophiid recently collected from an underwater cliff face of the Ashley River, South Carolina, USA, is assigned to Agorophius pygmaeus. It derives from the base of the Ashley Formation (early Oligocene). The new specimen consists of most of the skull and periotics, which are well preserved and described for the first time in an agorophiid. The new specimen provides an opportunity to diagnose the Agorophiidae and place the genus and species within the phylogenetic context of the early odontocete radiation in the Oligocene, along with other taxa such as the Ashleycetidae, Mirocetidae, Patriocetidae, Simocetidae, Waipatiidae, and Xenorophidae. Based on this new understanding, Agorophiidae are known with certainty only from the early Oligocene of South Carolina, with other undescribed, potential agorophiid specimens from the Oligocene of the North Pacific region (Japan, Mexico, and Washington State).

Recent work on new anthracothere (Mammalia, Artiodactyla) specimens from the Jebel Qatrani Formation, early Oligocene, Fayum, Egypt, has revealed the presence of a new genus. Nabotherium new genus is described on the basis of a partial skull, several mandibular and maxillary specimens, and isolated teeth. The new genus exhibits a distinctive combination of features not seen in other Paleogene anthracotheres. The most noticeable characteristics of the new genus include the presence of large and well-developed upper and lower canines, caniniform third incisors, the presence of only a short diastema between the canine and first premolar, and broad, bunodont cheek teeth. This is in contrast to other contemporary anthracotheres, including other forms from the Fayum, which show a spatulate third incisor, a reduced canine, a much longer canine-premolar diastema, and more narrow, bunoselenodont cheek teeth. The presence of a relatively short rostrum with closely packed incisors, low-crowned and simple premolars, and low-crowned, bunodont molars indicates that members of the new genus would have been more efficient at crushing foods than slicing vegetation, and suggests a more varied herbivorous and frugivorous diet than was favored by other, more bunoselenodont Fayum anthracotheres.