The family Prionitidae Hyatt represents a major component of ammonoid faunas during the Smithian (Early Triassic), and the genus Anasibirites Mojsisovics is the most emblematic taxon of this family. Its stratigraphical range is restricted to the beginning of the late Smithian (Wasatchites distractus Zone). The genus is also characterized by an unusual cosmopolitan distribution, thus contrasting with most earlier Smithian ammonoid distributions that were typically restricted by latitude. Because the late Smithian witnessed an extinction of the nekton (e.g. ammonoids, conodonts) whose amplitude is equal to or larger than that of the end‐Permian crisis, the number of valid species that should be included in the genus Anasibirites becomes a highly relevant question when addressing this extinction at the highest possible taxonomic resolution. Based on a new extensive collection from Timor, the composition of the genus Anasibirites is herein revised with respect to its intraspecific and ontogenetic variations. Comprehensive morphological and biometric studies (c. 950 measured specimens) indicate that, of the c. 60 available species names, only two are valid, namely A. kingianus (Waagen) and A. multiformis Welter. Continuous ranges of intraspecific variation enable us to synonymize A. nevolini Zakharov, and A. angulosus (Waagen) with A. kingianus. The contribution of Anasibirites to species diversity during the late Smithian extinction is thus significantly less than previously estimated, therefore accentuating the severity of this event.

It is widely accepted that the effects of global sea‐level changes at the transition from the Devonian to the Carboniferous are recorded in deposits on the shelf of northern Gondwana. These latest Devonian strata had been thought to be poor in fossils due to the Hangenberg mass extinction. In the Ma'der (eastern Anti‐Atlas), however, the Hangenberg Black Shale claystones (latest Famennian) are rich in exceptionally preserved fossils displaying the remains of non‐mineralized structures. The diversity in animal species of these strata is, however, low. Remarkably, the organic‐rich claystones have yielded abundant remains of Ammonoidea preserved with their jaws, both in situ and isolated. This is important because previously, the jaws of only one of the main Devonian ammonoid clades had been found (Frasnian Gephuroceratina). Here, we describe four types of jaws of which two could be assigned confidently to the Order Clymeniida and to the Suborder Tornoceratina. These findings imply that chitinous normal‐type jaws were likely to have already been present at the origin of the whole clade Ammonoidea, i.e. in the early Emsian (or earlier). Vertebrate jaws evolved prior to the Early Devonian origin of ammonoids. The temporal succession of evolutionary events suggests that it could have been the indirect positive selection pressure towards strong (and thus preservable) jaws since defensive structures of potential prey animals would otherwise have made them inaccessible to jawless predators in the course of the mid‐Palaeozoic marine revolution. In this respect, our findings reflect the macroecological changes that occurred in the Devonian. [Correction added on 28 July 2016 after first online publication: In the Abstract, the sentence “Vertebrate jaws probably … in the Early Devonian” was amended]

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Abstract.-The Early Triassic vertebrate record from low paleolatitudes is spotty, which led to the notion of an 'equatorial vertebrate eclipse' during the Smithian. Here we present articulated ray-finned fishes (Actinopterygii), collected from the marine Lower Triassic Thaynes Group at three new localities in Elko County (Nevada, USA), which were deposited within the equatorial zone. From the Smithian of the Winecup Ranch, we describe two partial skulls of the predatory actinopterygian Birgeria (Birgeriidae), attributed to B. americana new species and Birgeria sp. Birgeria americana n. sp. is distinguished from other species by a less reduced operculogular series. With an estimated total length of 1.72-1.85 m, it is among the largest birgeriids. We confirm that Birgeria encompasses species with either two or three rows of teeth on the maxilla and dentary, and suggest that species with three well-developed rows are restricted to the Early Triassic. From the latest Smithian of Palomino Ridge, we present a three-dimensional, partial skull of the longirostrine predator Saurichthys (Saurichthyidae). This and other occurrences indicate that saurichthyids were common in the western USA basin. From the early late Spathian of Crittenden Springs, we describe a posterior body portion (Actinopterygii indet.). This find is important given the paucity of Spathian osteichthyan sites. We provide a summary of Early Triassic vertebrate occurrences in the United States, concluding that vertebrate fossils remain largely unstudied. The presence of predatory vertebrates in subequatorial latitudes during the Smithian confirms that Early Triassic trophic chains were not shortened and contradicts the 'equatorial vertebrate eclipse'.

We present the first quantitative palaeobiogeographical analysis in terms of distribution and abundance of Early Triassic ammonoids from the western USA basin during the Smithian, c. 1 myr after the Permian–Triassic boundary mass extinction. The faunal dataset consists of a taxonomically homogenized compilation of spatial and temporal occurrences and abundances from 27 sections distributed within the western USA basin. Two complementary multivariate techniques were applied to identify the main biogeographical structuring recorded in the analysed presence/absence data: additive cluster analysis using the neighbor‐joining algorithm (NJ) and non‐metric multidimensional scaling (NMDS). Regarding abundance data, a taxonomic diversity (sensu evenness) analysis was coupled with graphical comparisons of relative abundances of selected taxa. The identified relationships indicate that middle Smithian ammonoids of the western USA basin were geographically organized in terms of both distribution and abundance, with the biogeographical distinction of a southern and a northern cluster. This N–S structuring in the distribution and abundance of middle Smithian ammonoids is notably paralleled by the relative amount of siliciclastics, which suggests that clastic load of the water column was a major controlling factor. In marked contrast with the middle Smithian, the studied late Smithian ammonoid assemblages do not show any significant differences, whatever the depositional environment. This abrupt biogeographical homogenization, independent from intrabasinal facies heterogeneity, indicates a switch from regional to global drivers, associated with the well‐known late Smithian global extinction and remarkable cosmopolitan ammonoid distributions during that time.

Gladius-bearing coleoids are rare in the fossil record. For the Cretaceous period, these cephalopods are mainly recorded in a few Lagerstätten in Lebanon (Haqel, Hajoula, En Nammoura, and Sahel Aalma). Here, we study 16 specimens of gladius-bearing coleoids from these Upper Cretaceous Lebanese Lagerstätten to investigate their taxonomic diversity. Besides two species that were already reported (Dorateuthis syriaca and Glyphiteuthis libanotica), one new species is identified in the Cenomanian site of Hajoula: Rachiteuthis acutali n. sp., as well as another form of Glyphiteuthis from En Nammoura. Several studied specimens exhibit well-preserved soft-part characters. Among them, we document for the first time two transverse rows of sessile suckers in D. syriaca and we confirm the absence of tentacles, as well as the presence of a crop in this species. This strongly supports the phylogenetic proximity of D. syriaca with modern vampyropods rather than with modern decabrachians. In turn, the similarity in gladius morphology between this taxon and modern squids is regarded as convergent.

Two extensive collections retrieved from Exotic Blocks from West Timor have yielded several astonishingly well-preserved and highly diversified Smithian (Early Triassic) ammonoid faunas (Kashmirites fauna, Owenites fauna, Anasibirites fauna). A population approach on this material, with an emphasis on ontogeny and covariation of morphological characters, led to the unprecedented assessment of intraspecific variation for many species. Based on this, their synonymy is thoroughly discussed whenever possible. One new genus (Roopnarinites) and five new species (Paraspidites bicarinatus, Flemingites lidakensis, Subflemingites bihatiense, Baidites obesus and Churkites warei) are described. These results have a direct impact on the resolution and accuracy of biochronological correlations, as well as on the accuracy of diversity counts at the species level, which is important for potential future broad-scale diversity analyses. This material also provides highly valuable data for comprehensive biogeographical and phylogenetic studies hopefully to come. Finally, these new Timor data strengthen the singularly uniform biogeographical distribution of the Smithian ammonoid faunas within the Tethys.

The Alpstein (cantons of Appenzell Ausserrhoden, Appenzell Innerrhoden and St. Gallen, northeastern Switzerland) has been of great interest for geologists over the last decades because of its excellent outcrops. However, there was no comprehensive overview over its Cretaceous fossil content. Here, we describe the cephalopod associations, which are moderately to highly diverse in some strata of the Alpstein. Furthermore, we document the regional palaeoecological changes that occurred during the radiation of heteromorph ammonites (ancyloceratids, scaphitids, turrilitids). To examine the palaeoecological changes,