The evolutionary histories of plant and animal species are often tightly linked to geological histories. A key example is the closure of the Isthmus of Panama, which facilitated widespread biotic dispersal between North and South America after independent faunal assemblages had evolved within each region. Likewise, Andean uplift accelerated and, consequently, created many barriers that led to numerous lineage diversifications. Leaf-toed geckos (Phyllodactylidae: Phyllodactylus) represent an ideal model for exploring the impact of Isthmus of Panama closure and Andean uplift on their evolutionary history. We present the most complete time-calibrated phylogeny for this genus to date and reconstruct the biogeographical history of the group. Our phylogenetic hypotheses indicate that the North and Central American Phyllodactylus clade is older than the hypothesized time for the full Isthmus of Panama closure, and Phyllodactylus most probably dispersed over open ocean before full isthmus formation was complete. Andean uplift coincided with several divergence events, although not until the late Miocene, after many clades had already diverged. Associated instances of hidden diversity in the Andes were revealed in this reconstruction, indicating that the full extent of diversity is yet to be characterized fully. Identification of species complexes and paraphyly within Phyllodactylus has important conservation implications for the protection of these reptiles.

Serpentine girdled lizards of the genus Chamaesaura Schneider, 1801 (Squamata: Cordylidae) consist of six currently recognized taxa: five species, one with two subspecies. Within the genus, species are diagnosed by the presence or absence of forelimbs, number of digits, and scutellation. Populations occurring in the Central Plateau of Angola have long been considered Chamaesaura miopropus (Boulenger, 1895). Through the revision of historical material from the collections of the Carnegie Museum of Natural History and the American Museum of Natural History, we found that the Angolan population differs from C. miopropus in limb and cranial morphology. Considering these morphological differences, geographic isolation, and high rates of local endemism in the Angola plateau, we herein describe a new species from Angola, Chamaesaura nombo.

The Sao Tom & eacute; Green Mamba has long been considered one of the great enigmas of Gulf of Guinea herpetology, as the only specimens ever collected were destroyed or are missing. Here we report the rediscovery of one of these specimens, collected in 1885 by Adolfo M & ouml;ller and long thought lost, housed in the Museum and Institute of Zoology, Polish Academy of Sciences, Warsaw. A detailed re-examination of this specimen provides the first opportunity in over a century to reassess its morphology and clarifies historical ambiguities in Bedriaga's description, particularly morphology overlaps with continental Dendroaspis viridis. A detailed history of the specimen is also presented, as well as future research directions.

Results of our contribution “Assessment of the Linnaean type material of the Nose-horned viper, Vipera ammodytes (Linnaeus, 1758)” (Krecsák et al. 2024) were criticized by Wüster et al. (2025) and Böhme et al. (2025) as ‘process driven’ findings which may cause disruption and confusion. By emphasizing the imperative of nomenclatural parsimony, the authors argued that prevailing usage should overrule the principle of priority particularly in the case of a widely known venomous snake of public health importance. We discuss the “inconvenient truth”, the results of the bibliographic analysis complemented with a multivariate analysis of the morphological characteristics of V. ammodytes specimens throughout the species range, which ascertained the original proper description and type locality as detailed by Linnaeus and corrections of errors resulting from the superficial assessment of the Linnaean publications and the complete ignorance or only incidental assessment of the existing type material by the herpetological community. We show that the name change does not threaten stability or universality. While the name changes might prove a minor inconvenience, mainly in the herpetological community, we demonstrate that they will have no effect on standardized and regulated toxinological research and the medical community involved in the first aid and treatment of Nose-horned Viper envenoming. Similarly, we refute the argument of confounding the antivenom distribution and purchases and provide a hypothetical example of a change of species name and its implementation by an antivenom manufacturer.

Namibe Province in southwestern Angola is a recognized hotspot of reptile diversity and endemism associated with the Namib Desert and Angolan Escarpment. In recent years, extensive surveys have greatly improved our knowledge of the region's herpetofauna, leading to new species descriptions and distribution records. Here we provide an updated checklist and atlas of reptiles from Namibe Province, integrating data from recent surveys with a comprehensive literature review. We document 141 reptile taxa from 55 genera and 23 families, including 18 species endemic to Namibe Province. Taxonomic accounts are provided for all recorded species, including distribution maps and revised chresonomies. Recent advances in herpetological research are discussed, as well as biogeographic patterns and emerging conservation concerns.

International nomenclatural Rules are indispensable for zootaxonomy and the study and management of zoodiversity. However, the current International Code of Zoological Nomenclature does not provide operational Rules for the nomenclature of taxa above the rank superfamily, which hampers unambiguous and universal scientific communication about zootaxonomy and zoodiversity. It is more than time to remedy this situation, and to provide detailed Rules for the three main stages of the Nomenclatural Process of class-series nomina (assignment and availability; nomenclatural and taxonomic allocation; validity and correctness). However, the long delay in incorporating these nomina in the Code complicates this task. This should be done carefully, on the basis of a careful and critical analysis of the needs of taxonomy and of biology as a whole, and of the concepts, criteria and practices of nomenclatural systems. This analysis will be developed in the coming papers of this series.

The Code regulates the status of zoological nomina and nomenclatural acts. Its aim is to provide an explicit, precise and objective nomenclatural system for the unambiguous and universal naming of all zoological taxa recognised by taxonomists, so that, in the frame of a given classification, the nomen of each taxon is unique and distinct. It relies on a Nomenclatural Process consisting in four main stages: nomenclatural assignment and availability, nomenclatural and taxonomic allocation, nomenclatural validity and correctness, and registration of nomina and nomenclatural acts. Whereas the Code currently in force is based on six stated Principles, the Linz Zoocode Committee recognises 18 distinct ones, implemented throughout the Code but not mentioned as such in this text. We here submit proposals to the international community of zootaxonomists, in the perspective of their incorporation into the next version of the Code. Particular attention is devoted here to 11 Principles, those of Availability, Nominal-Series, Coordination, Neonymy, Onomatophores, Zygoidy, Homonymy, Synonymy, Sozoidy, Archoidy and Registration. [1] Principle of Availability: [1.1] we stress its relevance not only for nomenclatural acts but also for taxonominal (both taxonomic and nomenclatural) acts, in order to avoid ambiguity and disagreements regarding the availability of the latter when published electronically; [1.2] we do not support the recent proposal of the Commission to replace in the Code the term ‘valid’ by the term ‘accepted’, as this would imply confusion between the concepts of availability and validity. [2] Principle of Nominal-Series: [2.1] we support the distinctions between nomenclatural ranks and taxonomic categories, and between nomenclatural ranks and nominal-series; [2.2] we distinguish taxa which are in a direct relationship of hierarchy in a given classification (being superordinate, parordinate or subordinate to each other) from taxa which have no direct hierarchical or sister-taxa relationship (being alienordinate); [2.3] we argue that the Code should require that, in any given classification, nominal-series do not overlap hierarchically and that the same Rule should apply, within each of them, among nomenclatural ranks, so that parordinate taxa be always assigned the same nomenclatural rank in the same nominal-series. [3] Principle of Coordination: we argue that it should not be implemented in the class-series, except in the case of a taxon that includes only one taxon of the just subordinate rank. [4] Principle of Neonymy: [4.1] we distinguish the concept of ‘nomen’ (scientific name) from that of ‘paronym’ (avatar of a nomen), the paronyms of a nomen including its ‘protonym’ (original paronym) and ‘aponyms’ (subsequent paronyms); [4.2] we support the introduction in the Code of the terms ‘neonym’ (nomen novum), ‘archaeonym’ (nomen for which a neonym has been established) and ‘allelonym’ (one of two or more alternative nomina used in the same work for the same taxon); [4.3] we consider that the Code’s concepts of ‘unjustified emendation’ and of ‘new replacement name’ are just two kinds of neonyms, respectively ‘autoneonym’ and ‘alloneonym’, which should be submitted to the same nomenclatural Rules; [4.4] we suggest that the current Rules concerning neonyms and apographs are unclear and insufficient, and should be improved. [5] Principle of Onomatophores: [5.1] we support the replacement in the Code of the term ‘type’ by the term ‘onomatophore’, with two main categories, ‘onymophoront’ (nomen-bearing specimen) and ‘nucleomen’ (nomen-bearing nominal taxon); [5.2] we stress that the taxonomic allocation of nomina under the Code is made through bidirectional (both inclusive and exclusive) ostension, not only by inclusive ostension or by intension or extension. [6] Principle of Zygoidy: we support the introduction in the Code of the nomenclatural concept of zygoidy to designate all situations of nomenclatural conflict for validity or correctness between two nomina, spellings or onomatophore designations. [7] Principle of Homonymy: we propose a detailed classification of the different kinds of homonymy recognised by the Code within (but not between) the different nominal-series. [8] Principle of Synonymy: [8.1] the concept of synonymy, which applies only between nomina of the same nominal-series, is a nomenclatural (objective synonymy) or taxonominal (subjective synonymy) concept, not a purely taxonomic one; [8.2] two nomina applying to the same taxon but assigned to different nominal-series are not synonymous but ‘synotaxic’. [9] Principle of Sozoidy: we argue that the conditions of the Code for the interpretation of ‘reversal of precedence’ are too permissive and should be replaced by conditions based on precise ‘categories of usage’ of nomina in the literature. [10] Principle of Archoidy: we note that the Commission has the power to invalidate permanently a nomen or a nomenclatural act, but not to validate a nomen permanently, as even a nomen entered in an Official List, if found to be a junior synonym or homonym of another available nomen, may later be invalidated. [11] Principle of Registration: we are very sceptical about the long-term permanency of electronic documents in view of the various threats that they already face, which may become much worse in the coming decades, and we think that the information currently registered in the lists managed by the Commission should be mirrored in paper publications that should be deposited in several libraries in all major regions of the world.

South-western Angola hosts exceptional reptile diversity, yet the evolutionary processes driving this richness remain poorly understood. Here, we integrate phylogenetics, morphological analyses, and ecological niche modelling (ENM) to reassess species' limits and diversification within the Pachydactylus angolensis complex, the only strictly endemic Pachydactylus species complex in Angola. Time-calibrated phylogenies based on mitochondrial and nuclear markers reveal four deeply divergent mitochondrial lineages, which diversified during the Late Miocene (similar to 10 Mya), each associated with a distinct ecoregion and displaying 15%-21% ND2 divergence. Morphological traits show strong conservatism but exhibit subtle differences in cranial structure, tooth loci arrangement, body size, and dorsal coloration. Furthermore, the analyses of three nuclear genes (RAG-1, KIAA, and c-mos) suggest mito-nuclear discordance within the 'coastal' clade, possibly reflecting secondary contact following historical climatic oscillations. Aiming to better understand such mito-nuclear discordances we generated past climatic ecological niche models, which support long-term segregation during glacial periods and partial overlap during interglacials, consistent with cycles of isolation and expansion. Based on these results, we describe an endemic species from west-central Benguela Province, Pachydactylus leucocephalus sp. nov., and designate the southern 'coastal' lineage as a candidate species pending additional evidence. Our findings highlight previously unrecognized cryptic diversity and illustrate the importance of continued fieldwork and genomic research to refine species boundaries and set conservation priorities in Angola.

Contrary to a widespread belief, the Code does provide some Rules concerning class-series nomenclature (applying to nomina above the rank superfamily). However, except for a few isolated statements concerning homonymy (that are not part of a thorough system of regulations about it) and a few details about their spelling, they only concern the first stage of the Nomenclatural Process, nomenclatural availability. We surveyed the Code to establish which of its Rules apply, or could apply, to class-series nomenclature, and we provide comments about them and recommendations for changes that could be brought to make them more useful—pending our future suggestions about the possible adoption of a complete system for this nomenclature.

Palaeontologists use skeletal features to determine the sex of specimens, but this can be complicated due to the incompleteness of fossil remains. In fossil assemblages, sexual dimorphism may be present in the form of ornamentation or may occasionally be detected through multivariate analyses. Sex can sometimes be estimated when embryos or eggs are found within a female specimen or associated with the specimen (e.g. brooding behaviour), although other sex-specific traits are rarely preserved in fossils. Squamates exhibit hemipenal bulges that are externally observable in males. These structures typically do not leave traces in hard rock fossils, but may be preserved in amber. We describe two lizard specimens embedded in burmite amber, which preserve almost the entire integument, though skeletal remains are very incomplete. One specimen shows a swelling at the base of the tail, comparable to the hemipenal bulge in male squamates, suggesting the presence of paired copulatory organs or hemipenes. Hemipenes almost certainly originated in the ancestor of Squamata or in stem-Squamates during the Triassic Period and this fossil provides rare documentation of these structures in the mid-Cretaceous. Research on amber fossils continues to highlight the remarkable preservation of soft tissues, even when hard tissues are poorly preserved. In this paper, we followed high ethical standards for sourcing these controversial fossils, following the recommendations from the Myanmar working group of the Society of Vertebrate Paleontology.

Among squamates, hemipenes are known to evolve rapidly and exhibit diverse shapes, sizes, and ornamentation. Croaking geckos (Aristelliger) are unique among geckos in exhibiting mineralized structures (hemibacula) in their hemipenes. We here describe the gross morphology of the hemibacula of each currently recognized species of Aristelliger, document hemibacular histology, and report on hemibaculum development. We confirm the presence of hemibacula in all currently recognized species and demonstrate that three distinct morphologies correspond to three putative clades in the genus. Histology revealed that hemibacula are superficially similar to chondroid bone and composed of mineralized dense connective tissue covered in a thin layer of epidermis with alcian-positive cells embedded within a mineralized matrix. Additionally, we demonstrate that hemibacula do not develop until past the onset of sexual maturity and that hemibaculum length scales isometrically with body size. We hypothesize that hemibacula of Aristelliger develop via peramorphosis, a phenomenon also expressed in the cranial morphology of this genus. Additionally, we speculate on the functional significance of these enigmatic structures.

Angola remains one of the least explored countries in Africa, and several groups of reptiles still require taxonomic and phylogenetic revision. To shed light on the true diversity of geckos in this gecko diversity hotspot of southwestern Africa, we conducted fieldwork in some of the less explored coastal regions of southern Angola. As a result, we identified previously unknown populations of Namib day geckos (genus Rhoptropus) which represent candidate new species. Through a comprehensive revision of the group, we describe three new endemic Rhoptropus spp. from the northern region of Namibe Province in Angola, based on morphological, phylogenetic and biogeographic data: R. minimus sp. nov., R. megocellus sp. nov., and R. crypticus sp. nov. These findings contribute to a better understanding of the biogeographic patterns of gecko diversity in Angola, highlighting the importance of this region as a significant center of endemism and diversification in Africa.

We provide a complete overview of Linnaeus's herpetological writings with specific focus on a review of his 89 herpetology related publications. A short biographical summary focused on key episodes of the life of Linnaeus is presented to facilitate the herpetologist reader to place the Linnaean publications in chronological order and to understand in which period of Linnaeus's life as a scientist the particular work was issued, and thus comprehend the maturity of the different ideas in the particular publication(s). The development of his publications is presented from the initial idea Linnaeus had on a subject, through the elaboration of these subjects by his students and their publication as academic dissertations, to their revision and inclusion in the multi-volume publication 'Amoenitates Academicae'. The Linnaean publications containing his 222 available Amphibia names are discussed. We present a short history of binominals linked to Amphibia, the key characters in his classification of the class, and further provide an overview of the sources of the existing Linnaean type material.

Abstract As part of a nineteenth century scientific network, José Vicente Barbosa du Bocage regularly sent “duplicate” specimens from the zoological collections of the National Museum of Lisbon to natural history museums across Europe. These duplicates gained exceptional significance following the 1978 fire that destroyed the Lisbon Museum’s zoological collections, making them the last surviving representatives of its historical holdings. Despite their importance for taxonomic and nomenclatural stability, the full extent of Bocage’s duplicate specimens remains poorly documented. Here we present a comprehensive and integrative revision of the herpetological material sent by Bocage to the British Museum of Natural History. We assess its historical, taxonomic and nomenclatural value, providing an illustrated and annotated catalogue of type specimens. A total of 92 specimens representing 57 species were sent from Lisbon between 1864 and 1896, including 30 type specimens for 27 nominal taxa. We provide evidence for the correction of the type locality associated with the only surviving syntype of Agama anchietae, as well as the recognition of previously unknown types of Chioglossa lusitanica, Hylambates angolensis, Hylambates cynnamomeus, Cystignathus bocagii, Hyperolius insignis, Hyperolius huillensis, Hemidactylus cessacii and Ophirhina anchietae.

Recent surveys in southwestern Angola uncovered cryptic diversity within Pachydactylus caraculicus. Phylogenetic analyses of nuclear and mitochondrial DNA recover three distinct lineages. Two of these lineages, characterized by their typical banded dorsal pattern, show clear geographic structuring: a "northern" lineage corresponding to true P. caraculicus, and a distinct "southern" lineage extending into neighboring Namibia. The third lineage, sister to the clade of banded caraculicus, comprises morphologically divergent specimens resembling P. punctatus. All three lineages within the P. caraculicus complex are diagnosable based on morphological and coloration characters. We formally describe the two unnamed lineages of P. caraculicus as new species and discuss these findings in the biogeographic context of the Kaokoveld's lizard fauna.

We provide comments and suggestions on the first eight “significant challenges” for zoological nomenclature listed by the International Commission on Zoological Nomenclature in 2024. In particular, we express disagreements regarding six of them, dealing with the term parataxon and related ones, the concept of hemihomonymy, the term polynomen, the Principle of Zoological Independence, differentiation of zoological nomenclature and the pronounciation of nomina. This analysis allows to survey and discuss several basic concepts and terms of zoological nomenclature.

Speciation often results from the accumulation of reproductive isolation associated with lineage divergence, but secondary contact between diverged lineages can reshape the trajectory of speciation and reveal its underlying processes. The Indonesian island of Sulawesi is a tectonically complex island formed by the fusion of many paleo-islands, resulting in replicated cases of secondary contact among once-isolated lineages. Unlike secondary contact on continents where hybridization often results from unpredictable range shifts, Sulawesi's fauna presents a replicated set of geologically constrained natural experiments to test how the magnitude of evolutionary divergence predicts outcomes of secondary contact and hybridization. Using thousands of genome-wide loci from Eutropis sun skinks spanning Wallace's Line on Sulawesi and Borneo, we reconstructed a reticulate evolutionary history shaped by overwater dispersal, isolation, island fusion, hybridization, and character displacement. We delimited five distinct species (three undescribed) and uncovered multiple ancient hybridization events following island fusion leading to distinct outcomes. These outcomes-speciation reversal, parapatry, and sympatry putatively through reproductive character displacement-were associated with increasing levels of prior divergence consistent with evolutionary theory. Sympatry, specifically, was preceded by substantial introgressive hybridization and body size divergence that likely confers reproductive incompatibility. Together, these results provide empirical support for divergence-dependent tipping points along the speciation continuum. The sun skink radiation also includes a rare instance of reverse colonization of Borneo across Wallace's Line that established a narrowly divergent species with a uniquely intermediate body size absent from Sulawesi.

The insular agamid genus Coryphophylax Fitzinger in Steindachner, 1867, is endemic to the Andaman and Nicobar Islands in the Bay of Bengal, India. These diurnal lizards are currently represented by two putative species, Coryphophylax subcristatus (Blyth, “1860” 1861) and Coryphophylax brevicauda Harikrishnan, Vasudevan, Chandramouli, Choudhury, Dutta & Das, 2012. The species C. subcristatus is said to be distributed through the Andaman and Nicobar Islands, even across the Ten Degree Channel, which is a recognised biogeographic barrier. A reassessment of the taxonomy of C. subcristatus shows the population south of the Ten Degree Channel, for which the nomen Coryphophylax maximiliani Fitzinger in Steindachner, 1867 is available, to be distinct. The results are based on morphological data from museum material, including type specimens and mitochondrial 16S rRNA sequences. The members of the genus Coryphophylax are abundant and widespread across the islands and may serve as an illuminating example for studying the patterns of colonization and diversification across the Andaman and Nicobar Islands.