The Cloverly Formation is an important geologic unit for understanding the development of North American terrestrial landscapes and ecosystems, but the age of this unit is poorly constrained. We report U–Pb radiometric dates determined by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) and chemical abrasion thermal ionization mass spectrometry (CA-TIMS) from euhedral zircons derived from fluvial sandstone and bentonitic claystone. We reanalyzed published biostratigraphic, paleomagnetic, and radiometric datasets, which have generally disregarded younger (late Albian–Cenomanian) ages for the formation. New data reported in this study suggest that deposition of the Cloverly Formation spanned the Valanginian–Cenomanian stages (ca. 140 Ma–98 Ma), a longer time interval than the commonly cited Aptian–Albian depositional timeframe. The lowest member of the Cloverly Formation, the Pryor Conglomerate, was deposited ca. 140–130 Ma in response to the onset of the Sevier Orogeny shedding sediment from the west. The overlying Little Sheep Mudstone Member was deposited ca. 124–109 Ma in a time of low sediment supply. In the mid–late Albian to early Cenomanian (ca. 109–98 Ma), sediment sourced from the east was deposited as the Himes Member and Greybull Sandstone. Following this, the Sykes Mountain Formation began nearshore deposition as the Western Interior Seaway transgressed from the north. Our revised chronostratigraphic framework for the Cloverly Formation is congruent with tectonic subsidence analysis showing a rapid increase in accommodation space in the mid-Albian. We hypothesize that more intensive sampling may yield multiple fossil assemblages within the formation, paralleling its correlates to the south. Furthermore, we hypothesize that some poorly represented taxa will be synonymized with taxa from those same units now that their temporal equivalence has been demonstrated.

Xiphosurids are an archetypal group of chelicerates with extensive anatomical, physiological, and paleontological documentation. Despite this research, very little information is available concerning abnormal specimens of the group. Here we vastly increase the number of documented abnormal extant xiphosurids by identifying 17 specimens showing a range of abnormalities on the appendages, cephalothorax, thoracetron, and telson. These specimens include all extant species and the first documentation of abnormal Carcinoscorpius rotundicauda. We note that previous suggestions that the telson was the most commonly abnormal body part may reflect a speciesspecific bias and propose increased use of museum collections to understand these iconic organisms and their abnormalities.

It is well known that reptiles can act as paratenic hosts for parasites that use mammals as their definitive hosts. However, studies of potential paratenic hosts in the Caribbean have been temporally restricted to only diurnal species of lizards, thereby neglecting a dominant component of the nocturnal reptilian community: geckos. Many gecko species are human commensals with activity periods that overlap temporally with those of domestic cats, making them prime candidates as potential transport hosts for cat parasites. However, no studies have reported geckos as paratenic hosts for felid parasites on any Caribbean island. Here we report the first records of subcutaneous oligacanthorhynchid cystacanths on the Venezuelan Coastal Clawed Gecko (Gonatodes antillensis) based on specimens collected in Curaçao and Bonaire. The cysts were identified as belonging to the genus Oncicola, likely those of Oncicola venezuelensis. This study reports these geckos as a new host record for oligacanthorhynchid cystacanths, as well as Curaçao and Bonaire as new geographic locales for these acanthocephalan parasites. We additionally provide a review of saurian cystacanths, comparing the restricted taxonomic focus of transport hosts in Caribbean islands to the distribution of paratenic squamate hosts both in the Neotropics and globally. We find evidence that the ability of squamate reptiles to act as transport hosts is a pervasive feature across their Tree of Life, suggesting that these animals may serve as important vectors for transporting parasites between intermediate and definitive hosts.

Deinosuchus is a genus of large crocodylian that inhabited North America during the Late Cretaceous. This massive predator has become one of the most well-known prehistoric organisms, with a considerable amount of literature on its biogeography, ecology, and evolution published. However, ontogenetic changes of Deinosuchus and other species of extinct large, predatory crocodyliforms have remained poorly understood because of a lack of remains known from juvenile individuals and issues surrounding the ability of histological analysis of adult material to provide information on yearly growth. Here, I describe a tooth from a juvenile Deinosuchus estimated at less than 1m in total body length. As the first reported specimen of a juvenile Deinosuchus, to the author's knowledge, in the literature, the new fossil evinces the extremely small size of young individuals of this taxon compared to adults more than 8 m and 3,500 kg. Furthermore, the tooth shows that some morphological discrepancies existed between the dentition of juvenile and adult Deinosuchus individuals, including the size of the nutritive region. In addition to being the first specimen of Deinosuchus from northeastern North America described in detail, the tooth emphasizes the biological extremes of attaining large body size in Deinosuchus and may add support to the hypothesis that the ontogeny of gigantic crocodyliforms was characterized by extended periods of juvenile growth.