Triassic-Jurassic Lagerstatten in eastern North America record biotic and environmental changes that set the stage for the era of dinosaurian ecological dominance that lasted 136 million years. This paper describes the morphologic, systematic, stratigraphic, temporal, and environmental context of these extraordinary fossil assemblages within strata of the vast, paleotropical eastern North American Newark Supergroup. Formed during the initial rifting of the supercontinent of Pangea, these mostly lacustrine and fluvial deposits combine a super-abundance of tetrapod footprints, particularly those of dinosaurs, with a physical stratigraphy that reflects orbitally paced climate cyclicity, which in turn provides a high-resolution stratigraphy for most of the record. Some Newarkian footprint Lagerstatten are exceptional, displaying detailed scale patterns, associated body impressions, and, plausibly, feather homologues. These strata contain other Lagerstatten that yield superbly preserved insects, fishes, and reptiles. More conventional assemblages of skeletal remains, tracks, fishes, and plants also abound. Most Lagerstatten and other assemblages occur in sedimentary cycles that reflect the expansion and contraction of perennial lakes in monsoonal climates. Newark Supergroup faunal and floral assemblages, and the strata they come from, document consequential events during the early Mesozoic, most notably those surrounding the continental end-Triassic mass extinction and the ensuing Jurassic recovery.
With roughly 500 collected specimens, Green River is the most important post-K/Pg world site for fossil cockroaches. Two previously unknown fossil individuals from Rio Blanco County, the cosmopolitan character of the Early Eocene cockroach biota. The genus Phoetalia St & aring;l, 1874 currently contains two extant species described originally from the Caribbean and the Canary Islands, occasionally occurring as domestic pests and also in bird nests. At least two specimens of the fossil species have damaged forewings. This type of damage is frequently observed in living individuals of the related genera Panesthia Serville, 1831, Salganea St & aring;l, 1877 and Ancaudellia Shaw, 1925. The fragile distal parts of the tegmina and wings may break off when rubbing against the wood of the galleries in which they live. Biting by other individuals has not been observed, but cannot be excluded, as well as predation. This would be the first time such behavior of beneficial biting by other organisms has been recorded in fossil specimens. The presence of this species in several slabs at the Yale Peabody Museum, together with its absence from other major Green River collections (e.g., those deposited in the National Museum of Natural History, Washington, DC), suggests that species distribution varied locally among Green River Formation localities, reflecting intraformational biogeographic variation within Eocene ecosystems.
The Gilt Darter, Percina evides, has a widespread distribution in rivers and streams across the Eastern and Interior Highlands region of eastern North America. Phylogenomics and disparity of meristic traits led to the delimitation of five independently evolving lineages in the Percina evides species complex, which we formally describe here. We redescribe P. evides sensu stricto as distributed in tributaries and mainstem of the Ohio River upstream of the confluence with the Tennessee River. We describe four new species: Percina versicolor sp. nov. distributed in the upper Tennessee River system; Percina campestria sp. nov. distributed in tributaries of the lower Tennessee River in Alabama, Tennessee, and Mississippi; Percina hespera sp. nov. distributed in the Missouri, Meramec, and upper Mississippi River watersheds in Missouri, Wisconsin, and Minnesota; and Percina obscura sp. nov. distributed in the White and St. Francis River systems in Arkansas and Missouri. Species of the Percina evides complex have suffered from habitat degradation and populations of P. hespera in Iowa and Illinois, populations of P. evides in the upper White, Maumee, Cumberland, and Wabash Rivers, and populations of P. obscura in the upper White River of Arkansas are extirpated. Species in the Percina evides species complex are diagnosed through a combination of meristic traits and male nuptial coloration and all five species are reciprocally monophyletic in phylogenomic analyses.
The taxonomy of the Nearctic Catocala amica (H & uuml;bner) species complex is examined, revealing a total of four species. Catocala pinicola sp. nov. is described as new, and observations on the life histories of all species are presented. Diagnostic characters for the four species are provided. Type specimens are reassessed, and the publication history of the species complex is reviewed, with the designation of a neotype for C. amica to promote stability in the genus.
The Yale Peabody Museum contains an underappreciated assortment of marine reptile fossils from the Jurassic of Europe. We describe one such fossil, comprising two individually cataloged specimens (YPM VP 000340 and YPM VP 065978), which Othniel Charles Marsh received from Europe (possibly from Alfred Nicholson Leeds) in the late 1800s. The fossil is an ichthyosaur vertebra (YPM VP 000340) punctured through the notochordal pit by a large pliosaur tooth (YPM VP 065978). Morphological considerations, aided by high-resolution microcomputed tomography scanning and three-dimensional image-stacking, enable us to assign the tooth to a Pliosaurus Owen 1841 from the Late Jurassic. Subsequent stratigraphic considerations lead us to assign the vertebra to Ophthalmosauria Motani 1999. The fossil therefore confirms a direct trophic interaction between these taxa and may shed new light on the feeding and prey manipulation behavior of macrocarnivorous pliosaurids.
Southeastern North America harbors the richest freshwater biodiversity hotspot in the northern hemisphere and is home to numerous species with extremely narrow ranges. Among these are the six species of the Etheostoma chermocki species complex, which exclusively inhabit small streams spanning fewer than 100 square kilometers in Alabama, USA. One of these species, the Birmingham Darter Etheostoma birminghamense, was described in April 2025 from Valley Creek and its associated tributaries, which extend into the urban core of Birmingham, AL, and its suburbs. At least one population of E. birminghamense is feared extirpated, highlighting the imperilment of this microendemic species. Here, we report the results of recent collections that extend the range extension of E. birminghamense into Little Blue Creek, Nabors Branch, Halls Creek, and localities in the mainstem of Valley Creek. As previously hypothesized, occurrences of E. birminghamense are associated with exhumed Cambrian-Ordovician- and Mississippian-age carbonate units, which in Little Blue Creek appear only as pockets of exposed bedrock at the base of the channel and on the banks. Our observations demonstrate that E. birminghamense is distributed throughout the majority of the Valley Creek drainage, highlighting the need for rapid assessment of its conservation status.
We present a comprehensive phylogenetic taxonomy of Labridae (wrasses, parrotfishes, hogfishes, and weedwhitings), one of the most species-rich lineages of marine teleost fishes, comprising 676 species distributed across tropical and temperate nearshore habitats worldwide. Using a phylogeny of 415 species inferred using genomic markers as a foundation, we create a synthetic phylogeny of 590 species of Labridae by including an additional 175 species based on mitochondrial DNA gene trees, other phylogenetic studies, and explicit statements of relationships in taxonomic revisions. We establish phylogenetic definitions for Labridae and 12 major rini, Sparisomatini, Xyrichtyinae, Pseudolabrinae, and Julidinae. Our taxonomy places parrotfishes (Scarinae) as a clade within Labridae, aligning with phylogenetic studies conducted over the past two decades. Our synthetic phylogeny highlights that several traditionally recognized genera (e.g., Halichoeres, Coris, Thalassoma), particularly within Julidinae, are polyphyletic. This finding necessitates substantial taxonomic revisions of Labridae including description and elevation of 11 genera, 17 new species synonyms, and more than 150 changes to genus-species combinations. This phylogenetically informed taxonomy provides a framework for understanding character evolution and adaptation in Labridae while preserving nomenclatural stability through the retention of well-established clade names.
A half-century of investigations in deep-lake and littoral facies have produced a wealth of fossils, illuminating the trophic structure of the latest Triassic and Early Jurassic rift ecosystems in include representatives of all fundamental levels of the food chain: bacteria, algae, plants, mollusks, crustaceans, insects, fishes, and tetrapods. The superabundance of large theropod dinosaur footprints in near-shore lake environments, as exemplified at Dinosaur State Park, Rocky Hill, Connecticut, and the rarity of herbivore tracks in the same facies suggest that the aquatic food web was critically important to apex dinosaurian carnivores. We clarify the stratigraphy and elucidate the monsoonal expansion and contraction of perennial lakes at Dinosaur State Park, highlighting the importance of microbial mats that blanketed trackway surfaces. At basin scale, we document the facies-dependent distribution of large carnivorous dinosaur tracks (Eubrontes) in lake-margin strata. In contrast, large herbivorous dinosaur tracks (Otozoum) primarily occur in fluvial facies, more proximal to upland environments. The rarity of herbivorous tetrapod footprints in lake-margin environments may indicate that herbivores lived in dry-land, upland habitats, spent most of their time foraging along streams and rivers, or intentionally avoided lake shores frequented by large carnivores. Large theropods were opportunistic apex predators in littoral habitats, with a diet of fishes and the smaller tetrapods that also frequented lake margins. Rather than tearing through coniferous forests displaying a fierce raptorial lifestyle, as typically portrayed, the large carnivores of the Triassic-Jurassic circumAtlantic rift valleys likely spent most of their days at the beach, fishing.
Between 1990 and 2023, the author identified and analyzed 1,007 tick collections, comprising 9,920 specimens and at least 89 species, which are deposited in the Division of Entomology at the Yale Peabody Museum. This paper presents a catalog of the geographic, temporal, life stage, host, and related data from these specimens. A classified host-parasite list and geographic gazetteer of tick species are included.
A collection of 559 faunal remains excavated at sites of the Castel-Merle valley in France is reanalyzed in terms of taxonomy and skeletal elements represented. The bones are part of a collection of primarily Mousterian faunal and lithic materials excavated by George Grant MacCurdy and the American School for Prehistoric Research that is curated at Yale Peabody Museum. The Yale collection was recovered from Abri des Merveilles, Abri de la Souquette, and possibly other Castel-Merle sites between 1925 and 1930. Assemblages from these excavations are also curated at several other North American museums, as well as in several French repositories. This analysis summarizes the characteristics of the assemblage and is intended to encourage other researchers to study similar historical collections for information about Pleistocene hominin behavior and environments.
Pterygotid eurypterids are known for their large size and elongate chelicerae. The Silurian Bertie Group of upper New York State has yielded complete and fragmentary specimens of giant individuals of the pterygotid Acutiramus macrophthalmus indicating maximum body lengths over 2 m. Here we describe and illustrate large, isolated examples of the otherwise poorly documented genital appendages (type A and B, generally interpreted as female and male respectively) of this pterygotid. The rarity of complete specimens of Acutiramus affording a ventral view of the body compromises attempts to infer body length from the dimensions of the genital appendages. These appendages provide useful evidence of the interrelationships of pterygotids when used in combination with other characters.
Classification of the tremendous diversity of ray-finned fishes (Actinopterygii) began with the designation of taxonomic groups on the basis of morphological similarity. Starting in the late 1960s morphological phylogenetics became the basis for the classification of Actinopterygii but failed to resolve many relationships, particularly among lineages within the hyperdiverse Percomorpha. The introduction of molecular phylogenetics led to a dramatic reconfiguration of actinopterygian phylogeny. Refined phylogenetic resolution afforded by molecular studies revealed an uneven diversity among actinopterygian lineages, resulting in a proliferation of redundant group names in Linnean-ranked classifications. Here we provide an unranked phylogenetic classification for actinopterygian fishes based on a summary phylogeny of 830 lineages of ray-finned fishes that includes all currently recognized actinopterygian taxonomic families and 287 fossil taxa. We provide phylogenetic definitions for 90 clade names and review seven previously defined names. For each of the 97 clade names, we review the etymology of the clade name, clade species diversity and constituent lineages, clade diagnostic morphological apomorphies, review synonyms, and provide a discussion of the clade's nomenclatural and systematic history. The new classification is free of redundant group names and includes only one new name among the 97 clade names we review and describe, yielding a comprehensive classification that is based explicitly on the phylogeny of ray-finned fishes that has emerged in the 21st century and rests on the foundation of the previous 200 years of research on the systematics of ray-finned fishes.
