Papers by Juan Diego Daza
Zoological Journal of the Linnean Society, 2024
We describe a new species of miniaturized gecko (genus Pseudogonatodes) from the Peninsula de Par... more We describe a new species of miniaturized gecko (genus Pseudogonatodes) from the Peninsula de Paria in northeastern Venezuela. Externally, the new species resembles Pseudogonatodes furvus and Pseudogonatodes manessi, from the Sierra Nevada de Santa Marta in Colombia and the Central Coastal Range in Venezuela, respectively; however, it differs from these species in terms of molecular genetic data (12S rRNA, 16S rRNA, and c-mos), osteological characters, and scale counts. The new species is unique in skull osteology, and we adopt the term ‘telescoped’ from the literature to describe the overlap of bones in the snout, in particular the premaxilla fully separating the nasal bones and contacting the frontal bone. The new species is also the only known species of Pseudogonatodes with fused parietal bones. Using molecular data, we present the first phylogeny of Pseudogonatodes, including six of the nine species in the genus. The new species is sister to P. manessi, which is consistent with biogeographical patterns in the mountainous areas of northern Venezuela. The phylogenetic results also indicate that Pseudogonatodes guianensis is non-monophyletic and raise the possibility of resurrecting the name Pseudogonatodes amazonicus. However, large sampling gaps in Amazonia prevent us from rigorously assessing species limits and proposing a taxonomic change.
Anatomical Record-advances in Integrative Anatomy and Evolutionary Biology, Nov 20, 2009
The enormous variation of the orbit in lepidosaurs is better conceptualized in terms of compositi... more The enormous variation of the orbit in lepidosaurs is better conceptualized in terms of composition and configuration. Broadly, the orbit varies from having totally closed rim to being open posteriorly. Two processes are responsible for changes in the components of the circumorbital series, element loss and fusion. The resulting contacts among elements are the main factors determining orbital configuration. Here, we present a revision of the gekkotan circumorbital bones in the general context of the Lepidosauria. From observations of a sample of 105 species of gekkotans prepared using different techniques, we describe the main changes in the orbit and corroborate the presence or absence of some of the ambiguous elements such as the lacrimal and the jugal. The supraorbital bones of squamates are reviewed and some problems of homology are evaluated using recent phylogenenetic hypothesis.
Anatomical Record-advances in Integrative Anatomy and Evolutionary Biology, Jun 26, 2021
John Paul Richard Thomas is among the living herpetologists to have described the greatest number... more John Paul Richard Thomas is among the living herpetologists to have described the greatest number of new species of amphibians and reptiles, and his contributions to the herpetology of the West Indies, particularly the Greater Antilles, have been exceptional. His academic career followed an unusual path, having established a strong reputation and described 50 new taxa prior to beginning his doctoral studies. His career was strongly influenced by Albert Schwartz and later was characterized by extensive and fruitful collaboration with S. Blair Hedges. Thomas' contributions to the study of blind snakes have been noteworthy. In addition to describing 28 species of scolecophidians he has been a keen observer of blind snake morphology and his 1976 dissertation remains a valuable source of osteological data. We outline some of the highlights of the career of Richard Thomas and provide a bibliography of his scientific works and a listing of the 108 taxa of amphibians and reptiles described by him.
Journal of Herpetology, Sep 1, 2012
Zoological Journal of the Linnean Society, Jan 17, 2018
Comparative osteology of European lizards, and of European geckos in particular, is poorly known,... more Comparative osteology of European lizards, and of European geckos in particular, is poorly known, resulting in problems when trying to determine to species isolated bones found as fossils or as remains of prey in scats or pellets. In order to partly solve this issue, we here present a detailed comparative analysis of the cranial bones of the four most broadly distributed species of European gekkotans: Euleptes europaea, Hemidactylus turcicus, Mediodactylus kotschyi and Tarentola mauritanica. The skulls of these species display both a set of features that are typical for geckos in general and unique features that can be employed to identify isolated bones of all considered species. Diagnostic differences are found in almost every bone (except the squamosal, epipterygoid and stapes), leading to the creation of a detailed diagnostic key. The dentition also displays some interspecific differences, even though all four species share a similar general tooth morphology, with pleurodont teeth provided with two parallel cutting edges separated by a groove-like space. Such a dentition is consistent with an arthropod-based diet.
Zoological Journal of the Linnean Society, Mar 1, 2013
ABSTRACT Gobekko cretacicus, a Cretaceous lizard from the Gobi Desert of Mongolia, is a key fossi... more ABSTRACT Gobekko cretacicus, a Cretaceous lizard from the Gobi Desert of Mongolia, is a key fossil for understanding gecko phylogeny. We revisit this fossil using high-resolution X-ray computed tomography. The application of this imaging method reveals new information about sutures, bone shape, and structural details of the palate and basicranium. These data were used to assess the phylogenetic affinities of Gobekko in the context of an existing squamate data set. The effects of character ordering, search strategy, and the addition of another putative gekkonomorph (Hoburogekko suchanovi) on inferred gekkonomorph relationships were explored. Available specimens of G. cretacicus are skeletally mature but have unfused nasals, frontals, and parietals, and (possibly) a persistent basicranial fenestra. Some putative gekkonomorphs are not consistently supported as closer to crown clade gekkotans than to autarchoglossans. In a strict consensus both Gobekko and Hoburogekko form a polytomy with extant geckos. Some of the adult character states of Gobekko are observable in embryos of extant species. The evolution of tubular frontals and dentaries in gekkotans may be structurally related to the loss of the postorbital and supratemporal bars in this lineage. The complete lack of a parietal foramen, and presumably a light-sensitive parietal eye, in this clade is of interest and could indicate an early origin of nocturnality in geckos. © 2013 The Linnean Society of London
Anatomical Record-advances in Integrative Anatomy and Evolutionary Biology, Sep 30, 2022
Royal Society Open Science
We here describe a new gekkotan lizard from the earliest Eocene (MP 7) of the Dormaal locality in... more We here describe a new gekkotan lizard from the earliest Eocene (MP 7) of the Dormaal locality in Belgium, from the time of the warmest global climates of the past 66 million years (Myr). This new taxon, with an age of 56 Myr, together with indeterminate gekkotan material reported from Silveirinha (Portugal, MP 7) represent the oldest Cenozoic gekkotans known from Europe. Today gekkotan lizards are distributed worldwide in mainly warm temperate to tropical areas and the new gecko from Dormaal represents a thermophilic faunal element. Given the Palaeocene–Eocene thermal maximum at that time, the distribution of this group in such northern latitudes (above 50° North – the latitude of southern England) is not surprising. Although this new gekkotan is represented only by a frontal (further, dentaries and a mandibular fragment are described here as Gekkota indet. 1 and 2—at least two gekkotan species occurred in Dormaal), it provides a new record for squamate diversity from the earliest ...
Royal Society Open Science, Sep 1, 2016
The fossil record shows that iguanian lizards were widely distributed during the Late Cretaceous.... more The fossil record shows that iguanian lizards were widely distributed during the Late Cretaceous. However, the biogeographic history and early evolution of one of its most diverse and peculiar clades (acrodontans) remain poorly known. Here, we present the first Mesozoic acrodontan from Africa, which also represents the oldest iguanian lizard from that continent. The new taxon comes from the Kem Kem Beds in Morocco (Cenomanian, Late Cretaceous) and is based on a partial lower jaw. The new taxon presents a number of features that are found only among acrodontan lizards and shares greatest similarities with uromastycines, specifically. In a combined evidence phylogenetic dataset comprehensive of all major acrodontan lineages using multiple tree inference methods (traditional and implied weighting maximumparsimony, and Bayesian inference), we found support for the placement of the new species within uromastycines, along with Gueragama sulamericana (Late Cretaceous of Brazil). The new fossil supports the previously hypothesized widespread geographical distribution of acrodontans in Gondwana during the Mesozoic. Additionally, it provides the first fossil evidence of uromastycines in the Cretaceous, and the ancestry of acrodontan iguanians in Africa.
Journal of Herpetology, 2017
Abstract Lepidosaurian reptiles (squamates and rhynchocephalians) comprise one of the world's... more Abstract Lepidosaurian reptiles (squamates and rhynchocephalians) comprise one of the world's most diverse groups of tetrapods, with most of that diversity found in regions of the world that once formed the supercontinent of Gondwana. In this special section of the Journal of Herpetology, we present both review and original studies on the evolution of lepidosaurs from Gondwana. In this contribution, we provide a brief introduction to those studies and also present metadata collected from the Web of Science on the progress of the study of lepidosaurian evolution. The latter indicate a substantial increase of research interest in multiple aspects of lepidosaur evolution worldwide, with special increase for lepidosaurs from Gondwanan continents. We conclude by setting some of the main goals we hope to achieve in the study of lepidosaurs from Gondwana in the near future.
Science, 2020
Ancient amphibians preserved in amber Extant amphibians are represented by three fairly simple mo... more Ancient amphibians preserved in amber Extant amphibians are represented by three fairly simple morphologies: the mostly hopping frogs and toads, the low-crawling salamanders, and the limbless caecilians. Until the early Pleistocene—and for more than 165 million years—there was another group, the albanerpetontids. We know little about this group because amphibian fossils are poorly preserved, and previous specimens from this group are both rare and mostly badly damaged. Daza et al. describe a set of fossils preserved in amber showing that this group was unusual both in their habitat use (they may been climbers) and their feeding mode, which appears to have been convergent with the ballistic feeding now seen in chameleons (see the Perspective by Wake). Science , this issue p. 687 ; see also p. 654
We identify a presumed specimen of Sphaerodactylus in amber from the Zoological Research Museum A... more We identify a presumed specimen of Sphaerodactylus in amber from the Zoological Research Museum Alexander Koenig as being embedded in copal, rather than amber. Further, the specimen matches the morphology not of a Hispaniolan gecko, but of the extant Madagascan species Ebenavia boettgeri, which occurs in a known area of copal deposits.
Current Biology, 2021
Unusual morphology in the mid-Cretaceous lizard Oculudentavis Highlights d A new species of the r... more Unusual morphology in the mid-Cretaceous lizard Oculudentavis Highlights d A new species of the reptile in amber, Oculudentavis, is described d Oculudentavis is a bizarre lizard, not a bird d The bird-like appearance of Oculudentavis is due to convergence in skull proportions
Cuadernos de Herpetología, 2017
We report on the predation of Thecadactylus solimoensis (Squamata, Phyllodactylidae) by an owl, P... more We report on the predation of Thecadactylus solimoensis (Squamata, Phyllodactylidae) by an owl, Pulsatrix perspicillata (Aves, Strigiformes). Examination of pellets collected from a P. perspicillata roost contained a partial left maxilla of a gecko. The maxilla contained the following traits, which confirmed the identification of T. solimoensis : the large size of the maxilla, at least 27 tooth loci, a thickened medial side of the maxillary palatal shelf, a horizontal shelf at the base of the facial process, and blade like posterior process that does not taper abruptly. This is the first report of a gecko in the genus Thecadactylus being preyed upon by an owl.
The Anatomical Record, 2021
John Paul Richard Thomas is among the living herpetologists to have described the greatest number... more John Paul Richard Thomas is among the living herpetologists to have described the greatest number of new species of amphibians and reptiles, and his contributions to the herpetology of the West Indies, particularly the Greater Antilles, have been exceptional. His academic career followed an unusual path, having established a strong reputation and described 50 new taxa prior to beginning his doctoral studies. His career was strongly influenced by Albert Schwartz and later was characterized by extensive and fruitful collaboration with S. Blair Hedges. Thomas' contributions to the study of blind snakes have been noteworthy. In addition to describing 28 species of scolecophidians he has been a keen observer of blind snake morphology and his 1976 dissertation remains a valuable source of osteological data. We outline some of the highlights of the career of Richard Thomas and provide a bibliography of his scientific works and a listing of the 108 taxa of amphibians and reptiles described by him.
Oculudentavis khaungraae was described based on a tiny skull trapped in amber. The slender taperi... more Oculudentavis khaungraae was described based on a tiny skull trapped in amber. The slender tapering rostrum with retracted osseous nares, large eyes, and short vaulted braincase led to its identification as the smallest avian dinosaur on record, comparable to the smallest living hummingbirds. Despite its bird-like appearance, Oculudentavis showed several features inconsistent with its original phylogenetic placement. Here we describe a more complete, specimen that demonstrates Oculudentavis is actually a bizarre lizard of uncertain position. The new interpretation and phylogenetic placement highlights a rare case of convergent evolution rarely seen among reptiles. Our results re-affirm the importance of Myanmar amber in yielding unusual taxa from a forest ecosystem rarely represented in the fossil record.
Journal of Morphology, 2019
Armored skin resulting from the presence of bony dermal structures, osteoderms, is an exceptional... more Armored skin resulting from the presence of bony dermal structures, osteoderms, is an exceptional phenotype in gekkotans (geckos and flap-footed lizards) only known to occur in three genera: Geckolepis, Gekko, and Tarentola. The Tokay gecko (Gekko gecko LINNAEUS 1758) is among the best-studied geckos due to its large size and wide range of occurrence, and although cranial dermal bone development has previously been investigated, details of osteoderm development along a size gradient remain less well-known. Likewise, a comparative survey of additional species within the broader Gekko clade to determine the uniqueness of this trait has not yet been completed. Here, we studied a large sample of gekkotans (38 spp.), including 18 specimens of G. gecko, using X-rays and high-resolution computed tomography for visualizing and quantifying the dermal armor in situ. Results from this survey confirm the presence of osteoderms in a second species within this genus, Gekko reevesii GRAY 1831, which exhibits discordance in timing and pattern of osteoderm development when compared with its sister taxon, G. gecko. We discuss the developmental sequence of osteoderms in these two species and explore in detail the formation and functionality of these enigmatic dermal ossifications. Finally, we conducted a comparative analysis of endolymphatic sacs in a wide array of gekkotans to explore previous ideas regarding the role of osteoderms as calcium reservoirs. We found that G. gecko and other gecko species with osteoderms have highly enlarged endolymphatic sacs relative to their body size, when compared to species without osteoderms, which implies that these membranous structures might fulfill a major role of calcium storage even in species with osteoderms.
Breviora, 2018
We report the discovery of a new genus and species of amber-preserved lizard from the mid-Cretace... more We report the discovery of a new genus and species of amber-preserved lizard from the mid-Cretaceous of Myanmar. The fossil is one of the smallest and most complete Cretaceous lizards ever found, preserving both the articulated skeleton and remains of the muscular system and other soft tissues. Despite its completeness, its state of preservation obscures important diagnostic features. We determined its taxonomic allocation using two approaches: we used previously identified autapomorphies of squamates that were observable in the fossil; and we included the fossil in a large squamate morphological data set. The apomorphy-based identification of this specimen, including comparative data on trunk elongation in squamates, suggests its allocation to the stem-group Anguimorpha. Results from the phylogenetic analysis places the fossil in one of four positions: as sister taxon of either Shinisaurus crocodilurus or Parasaniwa wyomingensis, at the root of Varanoidea, or in a polytomy with Varanoidea and a fossorial group retrieved in a previous assessment of squamate relationships. It is clear that this fossil has many similarities with anguimorph squamates and, if this taxonomic allocation is correct, this fossil would represent the first amber-preserved member of stem Anguimorpha ever recorded, and the smallest known member of that group. It further emphasizes the role of amber inclusions in expanding our understanding of the diversity of Cretaceous lizard communities.
Anatomical record (Hoboken, N.J. : 2007), Jan 12, 2017
Well-resolved phylogenetic hypotheses and ontogenetic data are often necessary for investigating ... more Well-resolved phylogenetic hypotheses and ontogenetic data are often necessary for investigating the evolution of structural novelty. The Sphaerodactylidae comprises 12 genera of predominantly miniaturized geckos. The genera Aristelliger and Teratoscincus are exceptions, with taxa reaching snout-to-vent lengths far exceeding those of other sphaerodactylids. These two genera possess enigmatic, supraorbital ossifications-parafrontal bones-which are encountered nowhere else among squamates. At the time of their discovery, these structures were believed to be the result of evolutionary convergence. Although relationships between other sphaerodactylids remain unresolved, recent molecular and morphological data have supported a close relationship between Aristelliger and Teratoscincus. We investigated the ontogeny of parafrontal bones to better understand relationships between sphaerodactylid body size and the presence of parafrontals, and to evaluate whether ontogenetic data support the ...
Journal of Herpetology, 2017
The South American genus Homonota comprises 10 species of Broad-Headed Geckos that reach the aust... more The South American genus Homonota comprises 10 species of Broad-Headed Geckos that reach the austral limit for the Gekkota. Historically, morphological data have supported the monophyly of a group including Homonota and the Chilean genus Garthia, with the latter possibly embedded within the former. In contrast, molecular evidence indicates these two genera to be in separate clades and that Homonota is more closely related to the Leaf-Toed Geckos of the genus Phyllodactylus. Here, we analyze 592 morphological characters in Garthia, Homonota, and additional phyllodactylid geckos to evaluate their morphological similarities. Our results indicate that Homonota and Garthia share a great majority of both external and internal characters and are nearly indistinguishable on morphological grounds. These results are interpreted in the light of a recently published multigene molecular phylogeny, and they suggest the symplesiomorphic retention of many morphological states linked to miniaturization and terrestriality in Garthia and Homonota, and concomitant differentiation of the American Leaf-Toed Geckos. RESUMEN.-El género Homonota del sur de Amé rica del Sur comprende diez especies de gecos de cabeza ancha, alcanzando el límite austral para los Gekkota. Histó ricamente, los datos morfoló gicos han apoyado la monofilia de un grupo que incluye Homonota y el género chileno Garthia, con la posibilidad de que el género anterior estuviese contenido en el primero. Por otro lado, la evidencia molecular reciente indica que éstos dos géneros forman dos clados separados y que Homonota está más cercano a los gecos con dedos en forma de hoja del género Phyllodactylus. En este trabajo, analizamos 592 caracteres morfoló gicos en Garthia, Homonota, además de otros de la familia Phllodactylidae con el propó sito de evaluar las similitudes morfoló gicas. Nuestros resultados indican que Homonota y Garthia comparten la mayoría de caracteres externos e internos, y que son casi indistinguibles morfoló gicamente. Estos resultados son interpretados utilizando una filogenia molecular reciente de varios genes, y sugieren que Garthia y Homonota retienen una gran cantidad de simplesiomorfias, las cuales están asociadas a sus hábitos terrestres y a procesos de miniaturizació n, como también a su diferenciació n de los gecos americanos con dedos de hoja.
Uploads
Papers by Juan Diego Daza