RESUMO
Fossil remains provide useful insights into the long-term impact of anthropogenic phenomena on faunas and are often used to reveal the local (extirpations) or global (extinctions) losses of populations or species. However, other phenomena such as minor morphological changes can remain inconspicuous in the fossil record depending on the methodology used. In this study, we used the anole of Marie-Galante Island (Anolis ferreus) in Guadeloupe (French, West Indies) as a model to demonstrate how the morphological evolution of an insular lizard can be tracked through the Pleistocene/Holocene climatic transition and the recent anthropization of the island. We used a fossil assemblage of nearly 30 000 remains and a combination of anatomical description, traditional morphometry and geometric morphometrics. These fossils are attributed to a single taxon, most likely to be A. ferreus on the basis of morphological and morphometric arguments. Our results show the disappearance of a distinct (sub)population of large specimens that were about 25% larger than the modern representatives of A. ferreus We also demonstrate an apparent size stability of the main fossil population of this species since the Late Pleistocene but with the possible occurrence of a reduction in morphological diversity during the Late Holocene. These results highlight the impact of anthropic disturbances on a lizard whose morphology otherwise remained stable since the Late Pleistocene.
Assuntos
Evolução Biológica , Lagartos/anatomia & histologia , Animais , Fósseis , Atividades Humanas , Humanos , Lagartos/genética , Índias OcidentaisRESUMO
Previous studies of color pattern, tongue pigmentation, and scale counts have been used to distinguish two species of semiaquatic varanids in Africa, but these findings have yet to be tested with molecular data. The Varanus (Polydaedalus) niloticus Species Group is comprised of the Nile monitor (V. niloticus) and the Ornate monitor (V. ornatus). Due to the high rate of exploitation of both species for bushmeat, the leather industry, and the pet trade, a clear understanding of the taxonomy and genetic partitioning is necessary for effective management. Here we utilize a multilocus approach, consisting of mitochondrial and nuclear markers, totaling 4251 bp, as well as microsatellite loci to assess the taxonomic validity and intraspecific evolutionary patterns within the V. niloticus Species Group. By incorporating historical specimens from museum collections as well as contemporary samples, we obtained range-wide coverage for both species across Africa. Concordant results from various approaches all suggest that V. ornatus does not represent a distinct monophyletic group. Our analyses recovered three genetic clades within V. niloticus, representing western, northern, and southern lineages. The western clade was found to diverge first, around 7.7 mya (95% HPD: 4.6-11.0 mya) and exhibits 8.4% and 8.7% uncorrected sequence divergence between the northern and southern V. niloticus clades, respectively. This geographically separate lineage corresponds to previous descriptions of Tupinambis stellatusDaudin (1802). These findings not only call for taxonomic revision of this species group, but also shed light on the biogeographic history of Africa as well as aid in the management planning of varanids and other co-distributed African species.
Assuntos
Variação Genética/genética , Lagartos/genética , África , Animais , Evolução Molecular , Repetições de Microssatélites , Dados de Sequência Molecular , Filogenia , Análise de Sequência de DNARESUMO
Africa is renowned for its biodiversity and endemicity, yet little is known about the factors shaping them across the continent. African Agama lizards (45 species) have a pan-continental distribution, making them an ideal model for investigating biogeography. Many species have evolved conspicuous sexually dimorphic traits, including extravagant breeding coloration in adult males, large adult male body sizes, and variability in social systems among colorful versus drab species. We present a comprehensive time-calibrated species tree for Agama, and their close relatives, using a hybrid phylogenetic-phylogenomic approach that combines traditional Sanger sequence data from five loci for 57 species (146 samples) with anchored phylogenomic data from 215 nuclear genes for 23 species. The Sanger data are analyzed using coalescent-based species tree inference using (*)BEAST, and the resulting posterior distribution of species trees is attenuated using the phylogenomic tree as a backbone constraint. The result is a time-calibrated species tree for Agama that includes 95% of all species, multiple samples for most species, strong support for the major clades, and strong support for most of the initial divergence events. Diversification within Agama began approximately 23 million years ago (Ma), and separate radiations in Southern, East, West, and Northern Africa have been diversifying for >10Myr. A suite of traits (morphological, coloration, and sociality) are tightly correlated and show a strong signal of high morphological disparity within clades, whereby the subsequent evolution of convergent phenotypes has accompanied diversification into new biogeographic areas.
Assuntos
Evolução Biológica , Lagartos/classificação , Filogenia , África , Animais , Teorema de Bayes , Núcleo Celular/genética , DNA Mitocondrial/genética , Funções Verossimilhança , Lagartos/genética , Modelos Genéticos , Dados de Sequência Molecular , Filogeografia , Análise de Sequência de DNARESUMO
Bronchocela jubata Dumril and Bibron, 1837 is one of the commonest species of the genus, known mostly from Java Island and southern parts of Sumatra. It is rare in Bali and Borneo. The juveniles are often confused with its morphologically similar congener, B. cristatella, which occurs widely throughout the Indonesian Archipelago and Peninsular Malaysia. We examined the morphology of B. jubata based on museum specimens including its two available syntypes, and redescribed the species based on the lectotype designated herein. We highlight the characters of B. jubata with a morphometric comparison to its sympatric congener B. cristatella from Java Island, Indonesia. Based on the current distribution pattern and the apparent threats, we update the conservation status of B. jubata using IUCN Red List Criteria, and propose that it be considered as a species of Least Concern (LC), endemic to the Greater Sundaic Islands.
Assuntos
Lagartos , Distribuição Animal , Animais , Indonésia , Museus , ÁrvoresRESUMO
Natural history museum collections hold extremely rare, extinct species often described from a single known specimen. On occasions, rediscoveries open new opportunities to understand selective forces acting on phenotypic traits. Recent rediscovery of few individuals of Bocourt´s Terrific Skink Phoboscincus bocourti, from a small and remote islet in New Caledonia allowed to genetically identify a species of land crab in its diet. To explore this further, we CT- and MRI-scanned the head of the holotype, the only preserved specimen dated to about 1870, segmented the adductor muscles of the jaw and bones, and estimated bite force through biomechanical models. These data were compared with those gathered for 332 specimens belonging to 44 other skink species. Thereafter we recorded the maximum force needed to generate mechanical failure of the exoskeleton of a crab specimen. The bite force is greater than the prey hardness, suggesting that predation on hard-shelled crabs may be an important driver of performance. The high bite force seems crucial to overcome low or seasonal variations in resource availability in these extreme insular environments. Phoboscincus bocourti appears to be an apex predator in a remote and harsh environment and the only skink known to predate on hard-shelled land crabs.
Assuntos
Braquiúros , Lagartos , Animais , Fenômenos Biomecânicos , Força de Mordida , Dieta , Humanos , Arcada Osseodentária/anatomia & histologia , Comportamento PredatórioRESUMO
Cryptic ecologies, the Wallacean Shortfall of undocumented species' geographical ranges and the Linnaean Shortfall of undescribed diversity, are all major barriers to conservation assessment. When these factors overlap with drivers of extinction risk, such as insular distributions, the number of threatened species in a region or clade may be underestimated, a situation we term 'cryptic extinction risk'. The genus Lepidodactylus is a diverse radiation of insular and arboreal geckos that occurs across the western Pacific. Previous work on Lepidodactylus showed evidence of evolutionary displacement around continental fringes, suggesting an inherent vulnerability to extinction from factors such as competition and predation. We sought to (1) comprehensively review status and threats, (2) estimate the number of undescribed species, and (3) estimate extinction risk in data deficient and candidate species, in Lepidodactylus. From our updated IUCN Red List assessment, 60% of the 58 recognized species are threatened (n = 15) or Data Deficient (n = 21), which is higher than reported for most other lizard groups. Species from the smaller and isolated Pacific islands are of greatest conservation concern, with most either threatened or Data Deficient, and all particularly vulnerable to invasive species. We estimated 32 undescribed candidate species and linear modelling predicted that an additional 18 species, among these and the data deficient species, are threatened with extinction. Focusing efforts to resolve the taxonomy and conservation status of key taxa, especially on small islands in the Pacific, is a high priority for conserving this remarkably diverse, yet poorly understood, lizard fauna. Our data highlight how cryptic ecologies and cryptic diversity combine and lead to significant underestimation of extinction risk. Supplementary Information: The online version contains supplementary material available at 10.1007/s10531-022-02412-x.
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Two cases of bites by a South African psammophiid snake, Psammophylax rhombeatus, are described and analyzed. These are the first detailed reports of local envenoming by a Psammophylax spp. While handling a wild-collected 1 m P. rhombeatus, the snake inflicted a protracted bite proximal to the metacarpophalangeal joint of digit #5, left hand of a 24-year-old male amateur herpetologist. Local edema persisted for three days, but no pain or other signs or symptoms including non-specific autonomic effects (e.g. headache, nausea) occurred. In a second case, a 28-year-old male herpetologist-photographer was repositioning a 0.58 m female P. rhombeatus in order to photograph the snake and her egg clutch, when the snake bit the metacarpophalangeal joint of digit #5, left hand, and briefly advanced its jaws. The bite caused mild local pain, progressive edema of the left hand, and arthralgia; resolution required almost 1 week. Bites from non-front-fanged snakes such as these by P. rhombeatus are uncommonly reported in comparison with those described for front-fanged snakes (e.g. Viperidae, Elapidae). Therefore, documentation of bites even with minimal effects provides information essential for the construction of an accurate medical risk profile for these less-known species.
Assuntos
Colubridae , Mordeduras de Serpentes , Adulto , Animais , Antivenenos , Edema/induzido quimicamente , Elapidae , Feminino , Humanos , Masculino , Dor , Mordeduras de Serpentes/tratamento farmacológico , Adulto JovemRESUMO
Blind snakes (Typhlopidae) are an enigmatic group of small burrowing snakes whose anatomy, phylogenetics, and biodiversity remain poorly known. Madatyphlops comorensis (Boulenger, 1889), endemic to the Comoros Archipelago in the Western Indian Ocean, is one of many species whose phylogenetic placement and generic assignment is unclear. We used DNA barcoding, external morphological examination, and osteological data from 3D reconstruction with micro-CT to study specimens of Madatyphlops from the Comoros Archipelago. Our results support the placement of M. comorensis in Madatyphlops and the recognition of the specimens from Mayotte Island as a closely related but distinct species, which we describe as Madatyphlops eudelini sp. nov. In this context, we present the first detailed osteological descriptions of any species of Madatyphlops, which we hope will serve as groundwork for further osteological studies in this genus and contribute to our limited but growing understanding of the osteology of typhlopid snakes.
Assuntos
Osteologia , Serpentes , Animais , Comores , Oceano Índico , Filogenia , Serpentes/genéticaRESUMO
Large-scale extinction is one of the defining challenges of our time, as human processes fundamentally and irreversibly reshape global ecosystems. While the extinction of large animals with popular appeal garners widespread public and research interest, the importance of smaller, less "charismatic" species to ecosystem health is increasingly recognized. Benefitting from systematically collected fossil and archaeological archives, we examined snake and lizard extinctions in the Guadeloupe Islands of the Caribbean. Study of 43,000 bone remains across six islands revealed a massive extinction of 50 to 70% of Guadeloupe's snakes and lizards following European colonization. In contrast, earlier Indigenous populations coexisted with snakes and lizards for thousands of years without affecting their diversity. Study of archaeological remains provides insights into the causes of snake and lizard extinctions and shows that failure to consider fossil-derived data probably contributes to substantial underestimation of human impacts to global biodiversity.
RESUMO
Climate has a large impact on diversity and evolution of the world's biota. The Eocene-Oligocene transition from tropical climate to cooler, drier environments was accompanied by global species turnover. A large number of Old World lacertid lizard lineages have diversified after the Eocene-Oligocene boundary. One of the most speciose reptile genera in the arid Palearctic, Acanthodactylus, contains two sub-Saharan species with unresolved phylogenetic relationship and unknown climatic preferences. We here aim to understand how and when adaptation to arid conditions occurred in Acanthodactylus and when tropical habitats where entered. Using whole mitogenomes from fresh and archival DNA and published sequences we recovered a well-supported Acanthodactylus phylogeny and underpinned the timing of diversification with environmental niche analyses of the sub-Saharan species A. guineensis and A. boueti in comparison to all arid Acanthodactylus. We found that A. guineensis represents an old lineage that splits from a basal node in the Western clade, and A. boueti is a derived lineage and probably not its sister. Their long branches characterize them-and especially A. guineensis-as lineages that may have persisted for a long time without further diversification or have undergone multiple extinctions. Environmental niche models verified the occurrence of A. guineensis and A. boueti in hot humid environments different from the other 42 arid Acanthodactylus species. While A. guineensis probably remained in tropical habitat from periods prior to the Eocene-Oligocene boundary, A. boueti entered tropical environments independently at a later period. Our results provide an important baseline for studying adaptation and the transition from humid to arid environments in Lacertidae.
Assuntos
Evolução Biológica , Genoma Mitocondrial , Lagartos/genética , Filogenia , Animais , Lagartos/classificação , Filogeografia , Clima TropicalRESUMO
The widespread parthenogenetic gecko Lepidodactylus lugubris is comprised of several clonal lineages, at least one of which has been known for some time to have originated from hybridization between its maternal ancestor, Lepidodactylus moestus, and a putatively undescribed paternal ancestor previously known only from remote islands in the Central Pacific. By integrating new genetic sequences from multiple studies on Lepidodactylus and incorporating new genetic sequences from previously sampled populations, we recovered a phylogenetic tree that shows a close genetic similarity between the generally hypothesized paternal hybrid ancestor and a recently described species from Maluku (Indonesia), Lepidodactylus pantai. Our results suggest that the paternal hybrid ancestor of at least one parthenogenetic clone of L. lugubris is conspecific with L. pantai and that the range of this species extends to Palau, the Caroline Islands, the Kei Islands, Wagabu, and potentially other small islands near New Guinea. Deeper genetic structure in the western (Palau, Maluku) versus eastern (eastern Melanesia, Micronesia, Polynesia) part of this species range suggests that the western populations likely dispersed via natural colonization, whereas the eastern populations may be the result of human-mediated dispersal. The potential taxonomic affinities and biogeographic history should be confirmed with further morphological and genetic analyses, including research on L. woodfordi from its type locality, which would have nomenclatural priority if found to be conspecific with L. pantai. We recommend referring to the wide-ranging sexual species as Lepidodactylus pantai until such a comparison can be made.
Assuntos
Lagartos , Animais , Hibridização Genética , Lagartos/genética , Partenogênese , FilogeniaRESUMO
Despite the small sample size the diversity of Rhabdias Stiles et Hassall, 1905 from anurans in the Afrotropical region was found to be high. Four species were collected from four localities, one in South Africa, two on Cameroonese mountains and one in Madagascar: Rhabdias picardiae sp. n. from the bufonid Amietophrynus gutturalis (Power); Rhabdias ohlerae sp. n. and Rhabdias tanyai sp. n. from the arthroleptids Leptopelis brevirostris (Werner) and Astylosternus rheophilus Amiet, respectively; and Rhabdias vencesi sp. n. from the mantellid Boophis madagascariensis (Peters). Distinctive characters between these species are numerous and obvious, based on body size, shape and size of the buccal capsule, arrangement of head papillae, and shape and size of the oesophagus and intestinal apex. Molecular data based on 500 bp of 12S rDNA and 600 bp of coxl of three of the four species are presented. Rhabdias vencesi resembles Rhabdias madagascariensis Chabaud, Brygoo et Petter, 1961 from an African ptychadenid introduced on Madagascar, but differs in body size and head morphology. The remaining new species are clearly distinct from those previously known from Afrotropical anurans. Outside the Afrotropics, some Rhabdias species present characters similar to those observed in the new species, but they all differ in various other characters. No clear correlation was seen between Rhabdias species and families of anuran hosts in this region. However, the narrow buccal capsule seen in Rhabdias species from Afrotropical lissamphibians opposes them to the majority of Rhabdias parasitic in chamaeleonids. Furthermore, the infective larva of R. vencesi has a conical pointed tail, while those of Rhabdias from chameleons have a rounded tail tip ornated with a few buds.
Assuntos
Anuros/parasitologia , Nematoides/anatomia & histologia , Nematoides/classificação , África , Animais , Feminino , Masculino , Nematoides/genética , Doenças Parasitárias em Animais/parasitologia , Especificidade da Espécie , Clima TropicalRESUMO
A recent case of a bite by a psammophiid snake, Psammophis schokari, is described and analyzed. This is the first report of local envenoming by this species. The 1 m long P. schokari inflicted a protracted bite on the third digit, right hand of the male 59 year-old victim who developed mild, but locally progressive edema and persistent pain; full resolution required almost three months. All documented cases of bites by snakes of the genus Psammophis are briefly reviewed and discussed. Finally, we encourage the use of a standardized method to describe the observed symptoms of bites by non-front-fanged colubroid snakes (NFFCs). Such bites are rare compared to those described for front-fanged snakes (e.g. Viperidae, Elapidae). Published data are still often comprised of anecdote or second-hand information. Whenever possible, formal medical evaluation of victims bitten by NFFCs should be performed in order to establish a medical risk and management profile for each species.
Assuntos
Mordeduras de Serpentes , Serpentes , Animais , Edema , Humanos , Masculino , Pessoa de Meia-Idade , DorRESUMO
Several recent papers have reviewed the life and work of French herpetologist Louis Amédée Lantz. They have detailed the composition of his collections deposited in several museums. However, since then, several other important specimens from his collections deposited at the Natural History Museum (NHM, UK) have come to light and we here present all of them in detail. We discovered paralectotypes of Lacerta saxicola obscura Lantz Cyrén (BMNH 1918.11.21.5-7), syntypes of Lacerta boemica Sukhov (BMNH 1960.1.4.26-30, BMNH 1965.337-342) and Lacerta viridis media Lantz Cyrén (BMNH 1960.1.4.25, 1966.512). We also identified numerous specimens from the French Mediterranean islands in Lantz's collection deposited at the NHM, some of which represent the first reported specimens of their species from certain islands. We here provide data on all these specimens. We also place the Mediterranean island specimens from the Lantz collection in their historical context and emphasize the historical and taxonomic value of these collections.
Assuntos
Lagartos , Museus , Animais , Londres , Ilhas do Mediterrâneo , História NaturalRESUMO
Only a single known specimen of Cnemaspis timoriensis (Duméril Bibron, 1836) exists, the holotype in the Muséum National d'Histoire Naturelle in Paris, France. Purportedly collected by Charles Gaudichaud-Beaupré in the year 1818 on Timor Island in the Lesser Sunda Archipelago during the circumnavigation of the globe by the vessel L'Uranie, intensive research on Timor has failed to produce additional specimens or any similarly appointed gecko. Using a series of detailed morphological comparisons, we provide irrefutable evidence that the animal in question is not a member of Cnemaspis but of the neotropical genus Gonatodes. Furthermore, we ascertained that C. timoriensis is conspecific with G. humeralis, a widely distributed South American species. We also show that a specimen labeled with the timoriensis name in the Museum für Naturkunde, Berlin, Germany is not conspecific and not part of a type series. While the taxon name timoriensis has nomenclatural priority over the two-decades-younger name humeralis, usage would dictate that to preserve the nomenclatural stability of neotropical geckos the junior synonym should be retained. An application to the International Commission on Zoological Nomenclature to this effect is in preparation.
Assuntos
Lagartos , Animais , Austrália , Berlim , França , Alemanha , Indonésia , Ilhas , ParisRESUMO
Atractaspidines are poorly studied, fossorial snakes that are found throughout Africa and western Asia, including the Middle East. We employed concatenated gene-tree analyses and divergence dating approaches to investigate evolutionary relationships and biogeographic patterns of atractaspidines with a multi-locus data set consisting of three mitochondrial (16S, cyt b, and ND4) and two nuclear genes (c-mos and RAG1). We sampled 91 individuals from both atractaspidine genera (Atractaspis and Homoroselaps). Additionally, we used ancestral-state reconstructions to investigate fang and diet evolution within Atractaspidinae and its sister lineage (Aparallactinae). Our results indicated that current classification of atractaspidines underestimates diversity within the group. Diversification occurred predominantly between the Miocene and Pliocene. Ancestral-state reconstructions suggest that snake dentition in these taxa might be highly plastic within relatively short periods of time to facilitate adaptations to dynamic foraging and life-history strategies.
Assuntos
Viperidae/classificação , Viperidae/genética , Estruturas Animais/anatomia & histologia , Estruturas Animais/fisiologia , Animais , Citocromos b/genética , Evolução Molecular , Genes Mitocondriais , Genes RAG-1 , Genes mos , NADH Desidrogenase/genética , Filogenia , Comportamento Predatório , RNA Ribossômico 16S/genética , Fatores de Tempo , Viperidae/fisiologiaRESUMO
We present information on primary type specimens for 13,282 species and subspecies of reptiles compiled in the Reptile Database, that is, holotypes, neotypes, lectotypes, and syntypes. These represent 99.4% of all 13,361 currently recognized taxa (11,050 species and 2311 subspecies). Type specimens of 653 taxa (4.9%) are either lost or not located, were never designated, or we did not find any information about them. 51 species are based on iconotypes. To map all types to physical collections we have consolidated all synonymous and ambiguous collection acronyms into an unambiguous list of 364 collections holding these primary types. The 10 largest collections possess more than 50% of all (primary) reptile types, the 36 largest collections possess more than 10,000 types and the largest 73 collections possess over 90% of all types. Of the 364 collections, 107 hold type specimens of only 1 species or subspecies. Dozens of types are still in private collections. In order to increase their utility, we recommend that the description of type specimens be supplemented with data from high-resolution images and CT-scans, and clear links to tissue samples and DNA sequence data (when available). We request members of the herpetological community provide us with any missing type information to complete the list.
Assuntos
Répteis , Animais , Bases de Dados FactuaisRESUMO
Cobras are among the most widely known venomous snakes, and yet their taxonomy remains incompletely understood, particularly in Africa. Here, we use a combination of mitochondrial and nuclear gene sequences and morphological data to diagnose species limits within the African forest cobra, Naja (Boulengerina) melanoleuca. Mitochondrial DNA sequences reveal deep divergences within this taxon. Congruent patterns of variation in mtDNA, nuclear genes and morphology support the recognition of five separate species, confirming the species status of N. subfulva and N. peroescobari, and revealing two previously unnamed West African species, which are described as new: Naja (Boulengerina) guineensis sp. nov. Broadley, Trape, Chirio, Ineich Wüster, from the Upper Guinea forest of West Africa, and Naja (Boulengerina) savannula sp. nov. Broadley, Trape, Chirio Wüster, a banded form from the savanna-forest mosaic of the Guinea and Sudanian savannas of West Africa. The discovery of cryptic diversity in this iconic group highlights our limited understanding of tropical African biodiversity, hindering our ability to conserve it effectively.
Assuntos
Elapidae , Genes Mitocondriais , África , África Ocidental , Animais , Florestas , NajaRESUMO
During travel made in February and March 1882 in the former French Protectorate of Côte d'Or (southeastern Ivory Coast), Mr Chaper, who had previously sent numerous specimens to the Paris Natural History Museum (Muséum national d'Histoire naturelle, Reptiles & Amphibiens; MNHN-RA), collected about 19 reptiles (and one python egg) belonging to 12 species. All those specimens were deposited in the MNHN-RA collections. Among them some specimens were described as a new species, Euprepes chaperi, in two separate publications reporting on that collection published in the same year by Vaillant (1884a,b), head of the Zoology (Reptiles and Fishes) Laboratory at Paris Natural History Museum. The status of that species was not recently reviewed and several options are reported in literature including validity of the species (in the genus Lygosoma Hardwicke & Gray) or synonymy, sometimes simultaneously in the same data base (see Uetz & Hosek, 2016). We here locate the type series of E. chaperi and carefully check their identity.
Assuntos
Serpentes , Estruturas Animais , Animais , Tamanho Corporal , Côte d'Ivoire , Tamanho do ÓrgãoRESUMO
The sporadic occurrence of localised pits on parietal plates was recently discovered in different colubrid genera of the subfamily Psammophiinae; these were considered to play a role in sensory perception. In the present study, we describe the presence of similar structures in Atretium schistosum, another colubrid snake reportedly not belonging to the Psammophiinae. As this species is suspected of being phylogenetically distantly related to psammophine snakes, some hypotheses are provided to explain (1) the putative function of these pits, (2) their sporadic occurrence, and (3) to suggest when they may have evolved in the colubroid snake clade.