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.

Malformed horseshoe crabs have been documented for over a century. However, most of these records are anecdotal observations of often striking morphologies recorded in isolation. There is therefore little understanding of how malformations are manifested and how they can develop in the group. Here we consider the molt sequences of three Limulus polyphemus individuals to explore different patterns of malformation development. One specimen with an injured telson demonstrates a gradual recovery of the telson section over three molting events. The second individual shows a thoracetronic injury incurred during at least molt-stage 7 that shows no evidence of recovery over five molting stages. The third individual demonstrates a fused thoracetron-telson articulation with a hole for the telson. This individual shows consistent growth of a reduced telson across molts. These records illustrate that horseshoe crab malformation recovery is far more complicated than previously thought. This also suggests that unless an exoskeletal section has functional morphological importance (i.e., the telson), the region is unlikely to recover from an older malformation. From a conservation standpoint, the ability or inability to fully recover from injury affects a horseshoe crab's ability to survive and/ or reproduce in the wild particularly if the injury affects the telson. Given the global decline in horseshoe crab populations and conservation efforts underway, the extent of injuries in extant populations of horseshoe crabs may affect population recovery and should be considered.

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.