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We present the fifth edition of the TimeTree of Life resource (TToL5), a product of the timetree of life project that aims to synthesize published molecular timetrees and make evolutionary knowledge easily accessible to all. Using the TToL5 web portal, users can retrieve published studies and divergence times between species, the timeline of a species' evolution beginning with the origin of life, and the timetree for a given evolutionary group at the desired taxonomic rank. TToL5 contains divergence time information on 137,306 species, 41% more than the previous edition. The TToL5 web interface is now ADA-compliant and mobile-friendly, a result of comprehensive source code refactoring. TToL5 also offers programmatic access to species divergence times and timelines through an application programming interface, which is accessible at timetree.temple.edu/api. TToL5 is publicly available at timetree.org.

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I describe a new species of frog, Eleutherodactylus montserratae sp. nov., from Montserrat, previously confused with E. johnstonei Barbour. It is native to that island and has been introduced, and established, on other Lesser Antillean islands west of 62 degrees west longitude including Anguilla, St. Martin/St. Maarten, St. Barthélemy, Saba, St. Eustatius, St. Christopher, and Nevis, as well as Bermuda. Previous chromosome and molecular studies have shown that populations from these islands are distinct from E. johnstonei, a species occurring east of 62 degrees west longitude in the Lesser Antilles, and elsewhere, but could not identify diagnostic morphological differences. Here, I show that the new species differs morphologically in being smaller (males and females) and having a proportionately larger tympanum, a wider head, and greater separation between the nostrils. Both species have been introduced within and outside of the Caribbean region and will likely expand their ranges in the future.

Assuntos

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A new genus and species of Caribbean forest lizard of the subfamily Celestinae Schools & Hedges are described. This new taxon is known only from two small adjacent keys in the Laguna de Oviedo of the Parque Nacional Jaragua in the Barahona Peninsula, Dominican Republic, at the southernmost region of the Caribbean island of Hispaniola. The genus Guarocuyus gen. nov. is genetically more closely related to the clade containing Celestus Gray, Comptus Schools & Hedges, and Panolopus Cope; nevertheless, we compare it to all celestine genera. Morphologically, it differs from other celestines by having an interdigital web on three toes and by having the widest ear opening. Additionally, the species Guarocuyus jaraguanus sp. nov. has some ecological attributes that when combined, appear to be unique, including nocturnal habits, a semiprehensile tail, and a facultatively arboreal lifestyle. We note sexual dimorphism in the new species and in two other celestines, Caribicus darlingtoni (Cochran) and the poorly known Celestus macrotus Thomas & Hedges, and report a range extension of the latter species into the Dominican Republic. We also discuss several scale topography conditions considered of taxonomic value for the group.

Assuntos

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The genus Arrhyton is endemic to Cuba, with eight currently known species. A new species, Arrhyton albicollum sp. nov., is described from the karst areas of Gibara, Holgun Province. The new species is closely related to A. redimitum, another eastern species, according to morphology and molecular phylogeny. It differs from all other species of the genus by having a conspicuous, white nuchal band, a contrasting black pattern on the head, a gray-colored body with faint stripes, and a high number of ventral and subcaudal scales. Additional comments on other species include new locality records and information on morphology and relationships.

Assuntos

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Lizards of the family Diploglossidae occur in moist, tropical forests of Middle America, South America, and Caribbean islands. Our analyses based on new molecular and morphological data indicate that the widely distributed genera Celestus Gray, 1839 and Diploglossus Wiegmann, 1834 are paraphyletic. We restrict the former to Caribbean islands and the latter to South America and Caribbean islands. We assign species in Middle America, formerly placed in Celestus and Diploglossus, to Advenus gen. nov., Mesoamericus gen. nov., and Siderolamprus Cope, 1861. We assign species on Caribbean islands, formerly placed in Celestus, to Caribicus gen. nov., Comptus gen. nov., Celestus, Panolopus Cope, 1862, Sauresia Gray, 1852, and Wetmorena Cochran, 1927. Our phylogenetic tree supports three major clades in the family: Celestinae subfam. nov. (Advenus gen. nov., Caribicus gen. nov., Comptus gen. nov., Celestus, Panolopus, Sauresia, and Wetmorena), Diploglossinae (Diploglossus and Ophiodes Wagler, 1828), and Siderolamprinae subfam. nov. (Mesoamericus gen. nov. and Siderolamprus). Our timetree indicates that the diploglossid lineage originated in the early Cenozoic and established three major centers of diversification in the Americas: Middle America (siderolamprines and one celestine), South America (diploglossines), and Caribbean islands (celestines and diploglossines). The majority of threatened species are on Caribbean islands, with the major threats being deforestation and predation by the introduced mongoose. Molecular and morphological data indicate that there are many undescribed species in this family of lizards.

Assuntos

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The skink genus Marisora ranges from Mexico to northern South America and occurs on some islands in the Caribbean Sea. We conducted a revision of the genus Marisora from Mexico and Central America, using new morphological and molecular data, and find support for the five previously described species (Marisora alliacea, M.aurulae, M. brachypoda, M. magnacornae, and M. roatanae) and describe four new species: Marisora lineola sp. nov., M. aquilonaria sp. nov., M. syntoma sp. nov., and M. urtica sp. nov. We show that two species previously known only from Central American islands, M. magnacornae and M. roatanae, also occur on the adjacent mainland and that two species recently placed in Alinea belong to this evolutionary clade: Marisora berengerae n. comb. and Marisora pergravis n. comb. Together with M. falconensis and M. unimarginata, these 13 species of Marisora arose mostly in the Pliocene and are largely allopatric but are sympatric and nearly sympatric at several locations in Central America where they maintain their morphological and genetic distinctiveness.

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Assuntos

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Tropical forests hold most of Earth's biodiversity. Their continued loss through deforestation and agriculture is the main threat to species globally, more than disease, invasive species, and climate change. However, not all tropical forests have the same ability to sustain biodiversity. Those that have been disturbed by humans, including forests previously cleared and regrown (secondary growth), have lower levels of species richness compared with undisturbed (primary) forests. The difference is even greater considering extinctions that will later emanate from the disturbance (extinction debt). Here, we find that Haiti has less than 1% of its original primary forest and is therefore among the most deforested countries. Primary forest has declined over three decades inside national parks, and 42 of the 50 highest and largest mountains have lost all primary forest. Our surveys of vertebrate diversity (especially amphibians and reptiles) on mountaintops indicates that endemic species have been lost along with the loss of forest. At the current rate, Haiti will lose essentially all of its primary forest during the next two decades and is already undergoing a mass extinction of its biodiversity because of deforestation. These findings point to the need, in general, for better reporting of forest cover data of relevance to biodiversity, instead of "total forest" as defined by the United Nation's Food and Agricultural Organization. Expanded detection and monitoring of primary forest globally will improve the efficiency of conservation measures, inside and outside of protected areas.

Assuntos

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Genomic data drive evolutionary research on the relationships and timescale of life but the genomes of most species remain poorly sampled. Phylogenetic trees can be reconstructed reliably using small data sets and the same has been assumed for the estimation of divergence time with molecular clocks. However, we show here that undersampling of molecular data results in a bias expressed as disproportionately shorter branch lengths and underestimated divergence times in the youngest nodes and branches, termed the small sample artifact. In turn, this leads to increasing speciation and diversification rates towards the present. Any evolutionary analyses derived from these biased branch lengths and speciation rates will be similarly biased. The widely used timetrees of the major species-rich studies of amphibians, birds, mammals, and squamate reptiles are all data-poor and show upswings in diversification rate, suggesting that their results were biased by undersampling. Our results show that greater sampling of genomes is needed for accurate time and rate estimation, which are basic data used in ecological and evolutionary research.

Assuntos

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Peltophryne armata sp. nov. is described from the South paleoisland of Hispaniola, West Indies. This is the only native toad species known to inhabit the Barahona Peninsula, Dominican Republic, in the southernmost part of Hispaniola, and it is allopatric with the widely distributed Hispaniolan toad species, P. guentheri Cochran. However, in a molecular phylogeny, the closest relative of P. armata sp. nov. is the Puerto Rican species P. lemur Cope, with which it shares a protrusive snout, large orbits, a depressed head, indistinct or absent infraorbital crests, and a long and complex advertisement call, but differs from it greatly by the very long cephalic crests, and in the massive and spinose parotoid glands that converge medially on the dorsum. The new species is similar in ecology and larval morphology to the Cuban P. florentinoi Moreno Rivalta, but differs from it in adult morphology. The tadpole of the new species is described. Peltophryne fracta is placed in the synonymy of P. guentheri.

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