Species in the beetle family Histeridae exhibit numerous defensive adaptations, from a generally compact and spheroid body shape to retractable tarsi, legs, heads, and antennae. Modes of antennal concealment are particularly variable, underscoring the importance of protecting these essential sensory structures. Understanding the evolution of these morphological features has been hindered by a weak

South Africa is currently home to a highly diverse tortoise assemblage whose evolutionary history has been investigated mostly as a result of molecular studies. The fossil record is of little help because the remains of extant taxa are relatively recent, and only three extinct species, of uncertain relationships, have been described so far. An Early Pliocene extinct species of the currently monotypic

The Zambezi grunter, Parauchenoglanis ngamensis, is currently distributed across four (sub)basins in southern and south-central Africa, namely the Okavango, upper Zambezi, Kwanza, and Kasai. The present study used a combination of molecular (barcoding), colour pattern, and other morphological data to explore the possible existence of hidden species diversity within this species. Based on the available

Research interest in the diversity and evolutionary history of herring-like fossils (subcohort Clupei) has increased in recent decades. However, little is known about the relationships between fossils assigned to Clupei, particularly those that are demonstrably related to extant herring-like members of the order Clupeiformes. To help bridge this gap, we present a new morphological phylogeny that includes

About 300 valid species are classified within the order Rajiformes, the largest group of chondrichthyans. The monophyly of this order is highly supported by morphological and molecular inferences, but little is known about the mandibular, hyoid, and hypobranchial muscles of its members. This study aims to describe and illustrate the morphological variation in mandibular, hyoid, and hypobranchial muscles

Fish skulls are often highly kinetic, with multiple linkage and lever systems powered by a diverse suite of muscles. Comparative analysis of the evolution of soft-tissue structures in the fish skull is often limited under traditional approaches, while new imaging techniques like diceCT (diffusible iodine-based contrast-enhanced computed tomography) allow for high-resolution imaging of muscles in situ

Synodontis Cuvier, 1816 is a species-rich group of African catfishes. Prior to this analysis, 13 species of Synodontis were recognized from Lake Tanganyika and its tributaries, composing the only extant lacustrine radiation of the genus, with a unique origin of obligate brood parasitism among all fishes. Species differentiation and phylogenetic relationships of this group remained largely unresolved

Cryptic species are black boxes of taxonomy and need to be addressed with an integrative taxonomic approach. Simulium (Diptera: Simuliidae) may contain a substantial amount of cryptic species diversity due to its large cross-continental distribution and habitat-based canalization in taxonomic characters. Except for Simulium sergenti, the following six species Simulium equinum, Simulium paraequinum

The predatory cladoceran Bythotrephes is one of North America’s most successful and impactive invasive species in freshwater plankton communities. The taxonomic status of the genus Bythotrephes Leydig, 1860 (Crustacea: Cladocera: Cercopagididae) has remained unclear and a subject of intensive debate for over 150 years. We applied an integrative taxonomy approach with multi-gene analysis (mitochondrial

We analysed phylogenetic relationships within a major clade of Cyprinodontiformes (Teleostei) that includes five families of North American killifishes. We used DNA sequences from five genes for 130 species, with four fossil calibrations and three secondary calibrations, to generate a time-calibrated phylogeny. We estimated diversification rates, ancestral areas, and ancestral habitats for each node

The Late Quaternary fossil record indicates that formerly in the North Atlantic volcanic Macaronesian archipelagos (Azores, Madeira, Selvagens, Canary Islands, and Cape Verde) there was a higher avian diversity, including numerous now extinct species. Currently, only three gadfly petrels (genus Pterodroma) remain in two archipelagos: the Fea’s petrel, Pt. feae, in Cape Verde (islands of Santiago, Fogo

The Palpimanidae are one of five extant Palpimanoidea families that occur mainly in South America and Africa, although there are lineages in Madagascar, islands of the Indian Ocean, and parts of Asia. Here we examine the role of plate tectonics in shaping the distribution of Palpimanidae. We perform molecular sequencing via target enrichment, which makes use of fragmented DNA, because most specimens

Anuran larvae are characterized by an extensive array of specialized oral structures that allow them to both graze on substrates and suspension feed with great efficiency. Diversity in these feeding structures accounts for significant diversity of anurans. Herein we describe an astonishing novel buccopharyngeal morphology in six larvae of ‘sand-eating’ tadpoles of the Mantellidae genus Mantidactylus

Arthroleptidae are an ecologically diverse group of sub-Saharan frogs. Arthroleptid tadpoles predominately occur in slow flowing to torrent waters. Their musculoskeletal system and the relationship between tadpole morphology and lifestyle are poorly understood. Here, we investigated the cranial morphology of four arthroleptid tadpoles occurring in different microhabitats: Leptopelis parkeri, Astylosternus

The Kem Kem Group is a lowermost lithostratigraphic unit from the Upper Cretaceous that extends along the border between Algeria and Morocco, in the northern region of Africa. This geological unit has yielded several tetrapod fossils, including a well-represented assemblage of theropod dinosaurs, after more than eight decades of research. Here, we report new occurrences of spinosaurid theropods from

Early Cretaceous ichthyosaurs were globally distributed pelagic marine reptiles, but many remains are fragmentary, creating a Northern Hemisphere diversity bias. A rich Hauterivian locality near the Tyndall Glacier inside Torres del Paine National Park in southern Chile yields important new data regarding ichthyosaurian diversity along the Pacific margin of Gondwana. These new data will contribute

In this study, we conduct a morphological integrative analysis, using traditional techniques and micro-computed tomography imaging, on Septibranchia species. Specimens deposited in malacological collections and samples collected aboard the research vessels Puerto Deseado and Austral off Mar del Plata (~36°S), San Jorge Gulf (~46°), and Marine Protected Area Namuncurá/Burdwood Bank area (~54°S), at

This study presents novel findings that expand our understanding of the evolutionary history and diversity of the Limoniidae subfamily Limnophilinae, with a specific focus on the relict genus Chilelimnophila. The family Limoniidae is well documented in the fossil record, with many species considered relicts in the modern fauna. Our study is based on the discovery of the first fossil specimens of Chilelimnophila

Species of Trypanosoma infecting reptiles are poorly understood and understudied. The study of trypanosomes infecting turtles could lead to a greater understanding of the genus and its evolutionary history. The present study re-evaluates and classifies two previously described species of Trypanosoma in freshwater pelomedusid turtles, Trypanosoma (Haematomonas) neitzi and Trypanosoma (Haematomonas)

Isolation of desert springs often leads to the evolution of unique biodiversity. We investigated the taxonomy and evolutionary relationships of members of the Gammarus pecos complex, an assemblage of narrowly endemic amphipod species in the Chihuahuan Desert of the USA. Morphological and molecular phylogenetic analyses, including newly obtained COI sequences from the now-extinct type population of

China is a hotspot for species’ discovery nowadays and harbours some of the most threatened environments in the world due to human activities. Here we describe a new remarkable gastropod species from an ancient freshwater lake in Yunnan, south-west China, Squamapex taiji gen. et sp. nov. within a new monospecific family of Truncatelloidea, Squamapicidae fam. nov.. The highly ornamented protoconch of

Unexpectedly abundant remains of herbivorous therapsids in the Late Triassic strata of southern Poland have significantly supplemented knowledge of their evolution. The skeletal morphology of the Late Norian (or Rhaetian) dicynodont Lisowicia bojani supports its close relationship to the Carnian Woznikella, both known from the Polish part of the Germanic Basin. Three evolutionary lineages of dicyn

Limnebius exhibits uniform external appearance but variable male genitalia: from differently curved rod shapes in the subgenus Bilimneus to up to seven longitudinally separated folds or appendages in Limnebius s.s.. Among nonsexual traits, two subgenera diverge only in the wing. The aedeagal complexity in Limnebius s.s. is associated with the secondary sexual structures on the abdomen and metatibia;

Ever since the discovery of Macrauchenia patachonica by Charles Darwin in 1834, the affinities of litopterns—a group of extinct South American Native Ungulates (SANUs)—have been elusive. In particular, the interfamilial relationships and timing of the familial diversification within the order Litopterna have not been addressed with adequate taxon and character sampling, and modern phylogenetic methods

Neotropical tetras of the family Characidae form the largest and most taxonomically complex clade within the order Characiformes. Previous phylogenetic relationships concur on the recognition of four major subclades, whereas knowledge on intergeneric and interspecific relationships remains largely incomplete or nonexistent. We sampled 575 specimens of 494 species and 123 genera classified in Characidae

The little-known western Eurasian taxa of the Phaedusinae (land snail family Clausiliidae) are Tertiary relicts, which are widely separated geographically from the rest of the subfamily occurring in eastern Eurasia. In order to elucidate the phylogenetic relationships of this group, we carried out molecular analyses with 11 of the 16 genera using nuclear gene sequences. Our results revealed that within

Aphids (Aphididae) are intensively studied due to their significance as pests and their captivating biological traits. Despite this interest, the evolutionary history of this insect family is poorly understood. Recent phylogenomic analyses have produced conflicting topologies, complicating our understanding of aphid trait evolution. In this work, we aimed to unravel the backbone phylogeny of aphids

Valettietta Lincoln & Thurston, 1983 (Amphipoda: Alicelloidea) is an infrequently sampled genus of scavenging amphipod, with a known bathymetric range from 17–5467 m encompassing a variety of habitats from anchialine caves to abyssal plains. Molecular systematics studies have uncovered cryptic speciation in specimens collected from the abyssal Pacific, highlighting uncertainty in the description of

A recent revision of the anacondas (Serpentes: Boidae: Eunectes), with the description of a new species of green anaconda, generated extensive publicity, but also provoked considerable controversy due to inadequacies of the evidence used and errors in nomenclature. We here use the case of this problematic publication to: (i) highlight common issues affecting species delimitations, especially an over-reliance

The Dodo and its extinct sister species, the Solitaire, are iconic exemplars of the destructive capabilities of humanity. These secondarily terrestrial columbids became extinct within a century of their first encounter with humanity. Their rapid extinction, with little material retained in natural history collections, led 18th and some early 19th century naturalists to believe that these aberrant birds

The stem lineage of Archosauria is populated by a diverse fossil record that remains notably understudied relative to the crown clade. Prominent among these specimens is a beautifully preserved skull of the early mid-Triassic rhynchosaur Mesosuchus browni [Iziko South African Museum (SAM) 6536], whose phylogenetic position has considerable influence on patterns of pan-archosaurian cranial evolution

Phengodidae (Coleoptera: Elateroidea), commonly known as glowworm beetles, are a small family of bioluminescent and paedomorphic beetles. There are few phylogenetic studies of Phengodidae, and these are mostly discordant, especially when comparing morphology-based and molecular-based phylogenetic hypotheses. Here, we used the anchored hybrid enrichment approach to undertake the first phylogenomic analysis

Here we report on anguimorph lizards from the earliest Eocene (MP 7) of the Dormaal locality in Belgium, from the time of the warmest global climate of the past 66 million years. Several clades can be identified in this site: Glyptosauridae, Varanidae, and Palaeovaranidae. Our study focuses on glyptosaurid specimens previously reported from the site, some of which had been provisionally described as

The egg tooth of squamates is a true tooth that allows them to break, tear, or cut the eggshell during hatching. In this clade there are some uncertainties concerning the egg tooth implantation geometry, the number of germs, and their fates during embryonic development. Here, we used X-ray microtomography and light microscopy, focusing on the egg tooth and remaining premaxillary teeth of the sand lizard

Trictenotomidae, one of the most charismatic and enigmatic groups of beetles, known for their large size and distinctive mandibles, is widely distributed throughout tropical and subtropical Asia. New species are continually being discovered, and the known range of the group has been expanded considerably by the discovery of Autocrates maqueti Drumont in the Korean Peninsula, ~2,000 km from its previously

A recent study on the freshwater planarian fauna of Corsica and Sardinia established that the formerly presumed single species Dugesia benazzii subsumed a complex of species. In that study, a thorough integrative taxonomic approach, combining molecular, morphological, and karyological data, uncovered the presence of two new endemic species. For the present study, additional samplings were conducted

The origin and evolution in the Southern Hemisphere of the Austral teals, consisting of the grey-teal and brown-teal species complexes, remains poorly understood owing to limited molecular data. With the group containing multiple independent examples of flight loss, understanding the evolutionary history of the group is of significant interest for functional genomic studies into the evolution of flightlessness

In this work, we present an integrative revision of the Lymnaeidae from the northeastern margin of Asia (Far East Russia, Japan, and Korea) and Alaska. According to our results, 14 native species inhabit this region, belonging to eight genera in two subfamilies (Lymnaeinae: Dallirhytis, Galba, Walhiana, Ladislavella, and Lymnaea; and Amphipepleinae: Kamtschaticana, Orientogalba, and Radix). Four of

The current classification system of the family Gryllacrididae primarily relies on morphological characteristics, with limited molecular studies conducted. In this study, we sequenced five genes (COI, COII, Cytb, 18S, and 28S) from a total of 46 gryllacridid individuals mainly from China. Subsequently, we utilized both the maximum likelihood method and the Bayesian inference method to construct a phylogenetic

Morphology is among the most important traits influencing the interaction of individual animals with their environments. Fossoriality reflects this functional association between morphology and the use of subterranean habitats and their associated environmental characteristics. Lizards in the families Gymnophthalmidae and Alopoglossidae are model organisms to examine the interplay between morphology

Sengis (Macroscelidea) are members of the Afroinsectivora, a group of mammals belonging to the supercohort Afrotheria. Sengis’ low population densities and their distribution, which includes politically unstable regions with ongoing armed conflicts, hinder contemporary sampling of comprehensive datasets. We overcome this obstacle for the species Petrodromus tetradactylus, one of the most widely distributed

Species are fundamental units of nature that need proper identification in order to assess and conserve biodiversity. Artemia is a model crustacean for population analysis and comparison in regionally endemic sexual species and parthenogenetic lineages distributed in hypersaline lakes, lagoons, and solar saltworks scattered in arid and semi-arid areas worldwide. The taxonomy of two American Artemia

Trigonosaurus pricei is a small to medium-sized sauropod dinosaur (Sauropoda: Titanosauria) from the Late Cretaceous Bauru Group of Brazil that is known from a significant amount of recovered axial elements [four cervical vertebrae, 10 dorsal vertebrae, sacrum (MCT 1488-R), and 10 caudal vertebrae (MCT 1719-R)]. In this biomechanical work, we approach the hypothesis of the cartilaginous neutral pose

Thalattosuchian crocodylomorphs were a ubiquitous component of shallow marine ecosystems during the Jurassic and Early Cretaceous. Alas, their origins remain a mystery. Here we describe three specimens from the Sinemurian (and possibly Early Pliensbachian) of the UK: a partial cranial rostrum, a series of cervical vertebrae, and two dorsal vertebrae adhered with matrix. These specimens are amongst

The freshwater mussels (Bivalvia: Unionida) of the biodiversity hotspot Sundaland are experiencing severe anthropogenic threats, whilst their diversity and distribution remain poorly understood. Here, we present the first modern-day data on Unionida diversity and distribution across western Borneo. Mussels were surveyed and collected in the upper Kapuas and Pawan river basins in West Kalimantan, Indonesia

Ciliated protists are unicellular eukaryotic organisms characterized by their morphological diversity, ubiquitous distribution, and the important roles they play in a wide range of biological studies. The class Litostomatea is a morphologically diverse ciliate group that comprises hundreds of free-living and endosymbiotic species. Here, we sequenced 14 predatory litostomateans, i.e. 12 haptorians and

The Holarctic land snail genus Perpolita was used to explore the influence of past and current biogeography on diversification. The number of empirically-supported species was determined using a consensus between mtDNA sequence, nDNA sequence, conchology, and geographic and ecological range with five valid temperate-boreal species (Perpolita binneyana, Perpolita electrina, Perpolita hammonis, Perpolita

The purpose of this paper is to describe a new species of Antarctic amphipod of the genus Orchomenella Sars, 1890, Orchomenella rinamontiae sp. nov., and to investigate whether high-resolution images of the surface anatomy obtained ‘in situ’ with synchrotron radiation X-ray phase-contrast micro-tomography (SR-PhC micro-CT) can replace classical approaches to describe a new species. The phylogenetic

Dacentrurus armatus was the first stegosaur described in the European Upper Jurassic at the end of the 19th century. The description of a second dacentrurine taxon, ‘Miragaia longicollum’, diagnosed from material non-comparable with the D. armatus holotype, has been controversial, and its validity has been challenged. In this study, we describe a new relatively complete stegosaurian postcranial skeleton

Spiders and ants are infrequent types of prey in the diet of spiders. Both spider- and ant-eating were found in thomisid (crab) spiders but their origin remains unclear. Our goal was to gather data on spider- and ant-eating habits in thomisid spiders, construct a family-level phylogeny, and estimate when these habits evolved. Using prey acceptance experiments, we found 21 spider- and 18 ant-eating

Acanthodes has long been the primary source of information on the pharyngeal skeleton of ‘acanthodians’. Because of this its anatomy has played a disproportionate role in attempts to understand the evolution of the jawed vertebrate pharynx and the clade as a whole. However, the anatomy of the pharynx of Acanthodes, now understood to be a stem-group chondrichthyan, remains poorly characterized and subject

The evolution of matrotrophic viviparity creates new scenarios within which evolutionary processes can operate, including postcopulatory events, family conflicts, and selective processes, which are expected to intensify with polyandry. We evaluated the effect of matrotrophic viviparity and polyandry on the reproductive output and offspring fitness of a bimodal reproductive vertebrate, the fire salamander

Urostomides is an obligate anaerobic ciliate genus in the family Apometopidae (Metopida). Although most congeners have been described using modern criteria, detailed ontogenetic data for both the family and genus have not been reported yet. In this study, we investigate the morphogenesis of two Urostomides species, viz., U. minimus (Kahl, 1927) comb. nov. and U. striatus (type species) in detail. Our

Cranial sutures, both open and closed, support a myriad of skull functions, including redistributing strain, accommodating brain expansion, supporting cranial bone growth, and protecting the brain. Thus, variation in the degree, timing, and pattern of suture fusion has functional implications. Using a comparative ontogenetic framework across Mammalia, we quantified degree and pattern of suture fusion

Neomphaloidean gastropods are endemic to chemosynthesis-based ecosystems ranging from hot vents to organic falls, and their diversity and evolutionary history remain poorly understood. In the southwestern Pacific, deep-sea hydrothermal vents on back-arc basins and volcanic arcs are found in three geographically secluded regions: a western region around Manus Basin, an eastern region around North Fiji

Based on high-resolution computed tomography scanning, we provide new insights into the inner ear and stapedial morphology of Morganucodon from the Early Jurassic of St Brides. At the base of mammaliaforms, Morganucodon plays a pivotal role in understanding the sequence of character acquisition from basal cynodonts to mammals, including the detachment of the middle ear and the evolution of high-frequency

Eurasian Giraffidae went through a drastic biodiversity decline after the Miocene–Pliocene boundary; scanty palaeotragine populations are likely to have survived in Central Asia, providing the necessary stock for a Late Pliocene–Early Pleistocene expansion from Central Asia to Spain and from the Mediterranean to southern Russia. Here, we describe new giraffid findings from the Greek middle Villafranchian

The Indian subcontinent houses a unique fauna of freshwater mussels. Tectonic and biogeographic reconstructions indicate that this fauna represents a derivative of Mesozoic Gondwanan biota and that it arrived in Asia on the Indian Plate, using this tectonic block as a ‘biotic ferry’. Though a preliminary integrative revision of the Indian Unionidae was published recently, the level of endemism and

Scaphander is a genus of mostly deep-sea, soft-bottom gastropods distributed nearly worldwide. Its taxonomic history is complex, with 32 species currently accepted, most based on shells only. In this work, we revise the diversity and systematics of Scaphander, with a focus on the Indo-Pacific region, using a detailed morphological study and molecular phylogenetics. Conchological and anatomical characters

New footage confirms Hemiceratoides moths to be bird tear-drinking. Bionomics of Hemiceratoides is updated, and its taxonomy revised, with descriptions of Hemiceratoides ornithopotis sp. nov. and H. avimolestum sp. nov., while Cynisca thysbe, type species of Siccyna (= Cynisca), is recombined as H. thysbe comb. nov. (thus Hemiceratoides = Siccyna synon. nov.), whereas another Siccyna, originally Cynisca