Insular Dwarfism Research Articles

Shrunken Life: Discourses of the Cryptic and the Miniature in Madagascar

As scientists scour remnant habitats and “unmask” cryptic species with DNA barcoding, a boom of species discovery has enchanted the world. In Madagascar, recent discoveries of previously unknown miniature frogs, chameleons, and lemurs often photographed on human fingers or cradled in hands, have captured the public imagination. In this imagery of scale, the giant finger conveys the outsized impact of humanity on Earth, or points to what Susan Stewart (1996, p. 74) calls “a physical world of disorder and disproportion.” Although the phenomenon of insular gigantism and dwarfism has shaped scientific discourses of evolution and extinction since the nineteenth century, recent reportage on “new” miniature and cryptic species reflects a sensibility beyond wistful nostalgia for creatures past. Species miniaturism evolves out of habitat loss, and living minifauna encapsulate the contraction of existential time, all the more pronounced by the effects of climate change. Photographs of cryptic minifauna therefore compel us to reflect on the whole of our losses, while they fuel the impulse to restock the “library of life” at micro-scale.

First report of leopard fossils from a limestone cave in Kenting area, southern Taiwan.

Longshia-dong Cave, a limestone cave located in the Kenting area within the Kenting National Park of southern Taiwan, yields numerous terrestrial mammalian fossils. Many of them were not reported in historical literature and are neither present in Taiwan. For instance, no historical literature mentioned leopards inhabited in Taiwan, and thus their existence remained unknown. This study describes three fossil leopard (Panthera pardus) teeth uncovered from Longshia-dong Cave. Two isolated lower premolars and one lower molar, respectively p3, p4 and m1, were discovered in a very small area (11 × 6 cm) and show a series of progressive increase in size. Thus, the three teeth should have been belonging to the same individual from the subfamily of Pantherinae. Traditional linear measurements and two-dimensional geometric morphometric analysis for the occlusal surface outlines were conducted on the fossil teeth and extant pantherines inhabited in Asia such as clouded leopards (Neofelis nebulosa), leopards (Panthera pardus), and tigers (Panthera tigiris). Results show that the fossil teeth are similar both in size and morphology to the teeth of extant leopards, suggesting the assignment of the fossil teeth to leopards. This study, for the first time, reported the presence of leopards in the Late Pleistocene of Taiwan. In addition, the smaller size of the fossil teeth in comparison with Chinese fossil leopards is putatively attributed to insular dwarfism or individual size variability, yet more studies are required.

Evolutionary treasures hidden in the West Indies: Comparative osteology and visceral morphology reveals intricate miniaturization in the insular genera Mitophis Hedges, Adalsteinsson, & Branch,2009 and Tetracheilostoma Jan, 1861 (Leptotyphlopidae: Epictinae: Tetracheilostomina).

The genera Mitophis and Tetracheilostoma comprise two extant lineages of small-sized threadsnakes that exclusively inhabit several islands of the West Indies. Even though leptotyphlopids are known for their extremely reduced size, miniaturization has only been hypothesized to reflect insular dwarfism for the genus Tetracheilostoma. Herein, we aim to describe the comparative osteology and visceral morphology of both genera, investigating and discussing their several internal morphological simplifications and novelties. Our results indicate that these taxa exhibit several autapomorphies mostly concentrated in the dorsoposterior skull elements and maxillae, as well as in their axial skeleton and viscera. These novelties and simplifications are most likely a result of extreme miniaturization driven by the evolutionary constraints or ecological opportunities possibly imposed by the "island rule." Both Mitophis and Tetracheilostoma distinguish from all other Epictinae in lacking a dentigerous process in the maxillae, by having the prootic fused to the otooccipital, and by the lack (except in comparison to a few Epictia) of a cervical vertebrae intercentrum I. Additionally, Mitophis can be distinguished from other Epictinae by the participation of the unpaired supraoccipital in the dorsal border of the foramen magnum, by the absence of the pleurapophyses in the caudal vertebrae, by a higher number of liver segments, and by the extreme degeneration of the pelvic rudiments. Tetracheilostoma differs from other Epictinae by lacking a distinct supraoccipital, which is fused to the parietal. Thus, our results reinforce that morphological characters are extremely valuable for leptotyphlopid systematics given their extremely conserved external morphology.

Phylogenetic relationships of the European trilophosaurids Tricuspisaurus thomasi and Variodens inopinatus

ABSTRACT Trilophosauridae are an extinct group of archosauromorphs from the Upper Triassic of western North America and Nova Scotia. Possible trilophosaurids Tricuspisaurus thomasi and Variodens inopinatus have also been reported from Upper Triassic fissure fills in the southwest of the United Kingdom, based on their multi-cuspid dentitions. Here, we provide an updated description of V. inopinatus and add to the description of T. thomasi, including re-examining CT scans of its holotype dentary. We confirm that the apparent gap on the dentary of T. thomasi is pathological, with the dentine of the teeth on either side of the gap asymmetrically thick, and that heavy vascularization of the anterior part of the dentary confirms it likely had a keratinous rhamphotheca. Our cladistic analyses, to which we add nine new characters, confirm that T. thomasi and V. inopinatus are closely related taxa and the youngest known trilophosaurids. Further, we support a previous suggestion that the relatively small size of these two European trilophosaurids results from insular dwarfism.

Quantitative genetics of extreme insular dwarfing: The case of red deer on Jersey

AbstractAimThe Island Rule—that is, the tendency for body size to decrease in large mammals and increase in small mammals on islands has been commonly evaluated through macroecological or macroevolutionary, pattern‐orientated approaches, which generally fail to model the microevolutionary processes driving either dwarfing or gigantism. Here, we seek to identify which microevolutionary process could have driven extreme insular dwarfism in the extinct dwarf red deer population on the island of Jersey.LocationJersey, UK (Channel Islands).TaxonRed deer (Cervus elaphus).MethodsWe applied an individual‐based quantitative genetics model parameterized with red deer life‐history data to study the evolution of dwarfism in Jersey's deer, considering variations in island area and isolation through time due to sea level changes.ResultsThe body size of red deer on Jersey decreased fast early on, due to phenotypic plasticity, then kept decreasing almost linearly over time down to the actual body size of the Jersey deer (36 kg on average). Only 1% of 10,000 replicates failed to reach that size in our simulations. The distribution of time to adaptation in these simulations was right skewed, with a median of 395 generations (equivalent to roughly 4 kyr), with complete dwarfism effectively occurring in less than 6 kyr 84.6% of times. About 72% of the variation in the time to adaptation between simulations was collectively explained by higher mutational variance, the number of immigrants from the continent after isolation, available genetic variance, heritability, and phenotypic plasticity.Main ConclusionsThe extreme dwarfing of red deer on Jersey is an expected outcome of high mutational variance, high immigration rate, a wide adaptive landscape, low levels of inbreeding, and high phenotypic plasticity (in the early phase of dwarfing), all occurring within a time window of around 6 kyr. Our model reveals how extreme dwarfism is a plausible outcome of common, well‐known evolutionary processes.

The island rule explains consistent patterns of body size evolution in terrestrial vertebrates.

Island faunas can be characterized by gigantism in small animals and dwarfism in large animals, but the extent to which this so-called 'island rule' provides a general explanation for evolutionary trajectories on islands remains contentious. Here we use a phylogenetic meta-analysis to assess patterns and drivers of body size evolution across a global sample of paired island-mainland populations of terrestrial vertebrates. We show that 'island rule' effects are widespread in mammals, birds and reptiles, but less evident in amphibians, which mostly tend towards gigantism. We also found that the magnitude of insular dwarfism and gigantism is mediated by climate as well as island size and isolation, with more pronounced effects in smaller, more remote islands for mammals and reptiles. We conclude that the island rule is pervasive across vertebrates, but that the implications for body size evolution are nuanced and depend on an array of context-dependent ecological pressures and environmental conditions.

Static allometry of a small-bodied omnivore: body size and limb scaling of an island fox and inferences for Homo floresiensis

Island dwarfing is a paraphyletic adaptation across numerous mammalian genera. From mammoths to foxes, extreme body size reduction is shared by diverse organisms that migrate to an island environment. Because it largely occurs owing to ecological variables, not phylogenetic ones, skeletal characters in a dwarfed taxon compared with its ancestor may appear abnormal. As a result, allometric patterns between body size and morphological traits may differ for an island dwarf compared with its ancestor. The diminutive Late Pleistocene hominin, Homo floresiensis, displays a unique character suite that is outside of the normal range of variation for any extinct or extant hominin species. To better explain these as ecological traits due to island dwarfing, this research looks at how dwarfing on islands influences limb scaling and proportions in an organism in a similar ecological niche as H. floresiensis. Here, I analyze absolute limb lengths and static allometry of limb lengths regressed on predicted body mass of dwarfed island foxes and their nondwarfed relatives. Dwarfed island foxes have significantly smaller intercepts but steeper slopes of all limb elements regressed on predicted body mass than the mainland gray fox. These allometric alterations produce limbs in the island fox that are significantly shorter than predicted for a nondwarfed gray fox of similar body mass. In addition, the humerofemoral, intermembral, and brachial indices are significantly different. These results provide a novel model for understanding skeletal variation of island endemic forms. Unique body size and proportions of H. floresiensis are plausible as ecological adaptations and likely not examples of symplesiomorphies with Australopithecus sp. Caution should be exerted when comparing an island dwarf with a closely related species as deviations from allometric expectations may be common.

Shrinking before our isles: the rapid expression of insular dwarfism in two invasive populations of guttural toad (Sclerophrys gutturalis).

Island ecosystems have traditionally been hailed as natural laboratories for examining phenotypic change, including dramatic shifts in body size. Similarly, biological invasions can drive rapid localized adaptations within modern timeframes. Here, we compare the morphology of two invasive guttural toad (Sclerophrys gutturalis) populations in Mauritius and Réunion with their source population from South Africa. We found that female toads on both islands were significantly smaller than mainland counterparts (33.9% and 25.9% reduction, respectively), as were males in Mauritius (22.4%). We also discovered a significant reduction in the relative hindlimb length of both sexes, on both islands, compared with mainland toads (ranging from 3.4 to 9.0%). If our findings are a result of natural selection, then this would suggest that the dramatic reshaping of an amphibian's morphology-leading to insular dwarfism-can result in less than 100 years; however, further research is required to elucidate the mechanism driving this change (e.g. heritable adaptation, phenotypic plasticity, or an interaction between them).

Diets of Pleistocene insular dwarf deer revealed by dental microwear texture analysis

Microwear is defined as the microscopic scars left during mastication on the surfaces of teeth. Because microwear reflects the physical properties of the food eaten by animal, it has been used for reconstruction of the diets of extinct animals. We investigated the dental microwear of the extinct insular dwarf deer Cervus astylodon using materials excavated from Late Pleistocene archaeological sites on Okinawa Island (the Hananda-Gama Cave site and the Yamashita-cho Cave I site). We applied three-dimensional surface texture analysis to quantitatively evaluate microwear features. We analyzed 293 individual sika deer (Cervus nippon) from 15 populations in Japan with quantitative dietary data clarified by rumen contents or feces analyses, constructing one of the most comprehensive microwear databases of extant ruminants. We found that deer with a higher consumption of graminoids showed rougher tooth surfaces than those browsing on trees owing to the high content of abrasive silica in graminoid leaves. Using a regression equation relating surface roughness parameters and the percentage of graminoids in the diet, we estimated that C. astylodon from the Hananda-Gama Cave might have consumed a diet consisting of approximately 44% graminoids, whereas we estimate a predominantly graminoid-based diet (ca. 78%) for deer from the Yamashita-cho Cave. Therefore, contrary to the findings of mesowear and stable carbon isotope analysis, which indicated a browsing diet, we propose that C. astylodon were mixed feeders or possibly grazers. These findings provided an important implication of their peculiar evolution on islands.

Late Triassic island dwarfs? Terrestrial tetrapods of the Ruthin fissure (South Wales, UK) including a new genus of procolophonid

ABSTRACT Ancient cave deposits across South Wales and southwest England have yielded Late Triassic to Early Jurassic tetrapod faunas that occupied a sub-tropical island archipelago. Here we present a hitherto little studied fissure at Ruthin Quarry in South Wales. A tooth of the primitive neoselachian shark Rhomphaiodon minor indicates the age of the fissure as early Rhaetian, some 205 Ma, possibly equivalent to the first bone-bed horizons in the Westbury Formation. We identify 11 taxa, including chondrichthyans, procolophonids including a new genus and species named here Smilodonterpeton ruthinensis, rhynchocephalians, the trilophosaurid Tricuspisaurus thomasi and archosaurs, including a small crocodylomorph like Terrestrisuchus. Ruthin is dominated by procolophonids and secondarily by archosaurs. Rhynchocephalians are rare at Ruthin, unlike at penecontemporaneous fissure localities. Many of these faunas are reminiscent of those found in Carnian-Norian deposits from North America, some of them 25 Myr older, suggesting the Ruthin faunas are relictual. In exploring the palaeogeography of Ruthin and other British Late Triassic fissure deposits, we find that factors in addition to island size may affect the recorded species richness of these islands. Further, most of the taxa appear to be ‘primitive’ (i.e. possess closest relatives that are much older stratigraphically), and their body sizes are small, so this could be the oldest record of insular dwarfism.

Defining the Island Dwarfing Rate of an Extinct Sicilian Elephant Using Ancient DNA

Evolution on islands, and the often extreme phenotypic changes associated with it, has attracted much interest from evolutionary biologists. However, measuring the rate of change of a particular phenotypic trait of extinct animals can be challenging, due to the incompleteness of the fossil record. Here, we use combined molecular and fossil evidence to define the minimum and maximum rate of dwarfing in an extinct Mediterranean dwarf elephant from Puntali Cave (Sicily). Despite the challenges associated with recovering ancient DNA from warm climates, we successfully retrieved a mitogenome from a sample with an estimated age between 147,000 and 50,000 years. Our results suggest that this specific Sicilian elephant lineage evolved from one of the largest terrestrial mammals in the Pleistocene to a comparatively small-bodied island species, with an estimated average mass reduction of 0.79 - 18.45 kg and height reduction of 0.15 - 3.41 mm per generation. We show that combining ancient DNA, palaeontological and geochronological evidence can constrain the timing of phenotypic changes within narrower age boundaries than could be achieved using any source of evidence in isolation.

Sexual maturity and growth of male toads (Rhinella ornata): A comparison between insular and mainland populations

We studied differences in age, longevity, and sexual maturity in island and mainland populations of the neotropical toad Rhinella ornata to assess how changes in sexual characteristics relate to evolution of insular dwarfism. Here we tested the hypothesis that effects of the island rule results in earlier sexual maturity. We sampled males from three insular (Ilha Grande, Ilha da Marambaia and Ilha de Itacuruçá) and four adjacent mainland sites in the state of Rio de Janeiro, Brazil. Age, estimated by skeletochronology, was contrasted to sexual classes defined based on observation of secondary sexual characters (i.e., nuptial excrescences). Individuals reached sexual maturity after one year and longevity was estimated at an age to be up to four years. The presence of nuptial excrescences was influenced by age and growth rate and varied between populations. Individuals from Ilha Grande reached reproductive maturity at smaller sizes than their co-specifics on the mainland. Age and longevity of R. ornata were in agreement with the data of other tropical frog species.

The smallest of the largest: new volumetric body mass estimate and in-vivo restoration of the dwarf elephant Palaeoloxodon ex gr. P. falconeri from Spinagallo Cave (Sicily)

ABSTRACT In the present paper we provide a new estimate of the body mass (BM) of the dwarf elephant Palaeoloxodon ex gr. P. falconeri from Spinagallo cave (Sicily) at three different ontogenetic stages. The new estimates are based on 3D in-vivo restorations, digitally sculpted on anatomically updated photogrammetric models of the skeletons mounted at the Museo Universitario di Scienze della Terra (MUST), University of Rome (Italy). The new method provided an average BM of 249.98 kg for the adult male, 150.47 kg for the adult female, 38.81 kg for the juvenile male and 7.83 kg for the new-born male. Assuming as reliable these estimates, the values previously obtained by applying the regression formulae based on pad circumferences, shoulder height and long bone circumferences substantially would underestimate or overestimate the Spinagallo elephant BM up to 103%. The results obtained indicate that the volumetric methods can be regarded as the most solid and reliable to estimate the BM in those extinct vertebrates for which accurate mounted skeletons are available. This new method is therefore of critical importance for inferring the BM of taxa characterised by peculiar osteological proportions, such as those shown by the insular dwarf elephant analysed in the present work.

Brain Changes during Phyletic Dwarfing in Elephants and Hippos

Of all known insular mammals, hippos and elephants present the extremes of body size decrease, reducing to 4 and a mere 2% of their ancestral mainland size, respectively. Despite the numerous studies on these taxa, what happens to their relative brain size during phyletic dwarfing is not well known, and results are sometimes conflicting. For example, relative brain size increase has been noted in the Sicilian dwarf elephant, Palaeoloxodon falconeri, whereas relative brain size decrease has been postulated for Malagasy dwarf hippos. Here, I perform an analysis of brain, skull, and body size of 3 insular elephants (Palaeoloxodon “mnaidriensis,” P. tiliensis, and P. falconeri) and 3 insular hippos (Hippopotamus madagascariensis, H. lemerlei, and H. minor) to address this issue and to test whether relative brain size in phyletic dwarf species can be predicted. The results presented here show that the encephalization of all insular elephants and hippos is higher than that of their continental relatives. P. falconeri in particular has an enormous encephalization increase, which has so far not been reported in any other insular mammal. Insular brain size cannot be reliably predicted using either static allometric or ontogenetic scaling models. The results of this study indicate that insular dwarf species follow brain-body allometric relationships different from the expected patterns seen for their mainland relatives.

Insular dwarfism in canids on Java (Indonesia) and its implication for the environment of Homo erectus during the Early and earliest Middle Pleistocene

Several canid fossils, which were originally discovered and described in the early 20th century, are known from Early and earliest Middle Pleistocene of Java (Indonesia). Here we revise the taxonomy and relative age of the Javanese canid fossils in light of recent developments in the taxonomy and phylogeny of Canidae, and new insights in the evolution of island mammals. Results show that Cuon was absent during the Early and earliest Middle Pleistocene while the large-sized Xenocyon (previously Megacyon) was present in the Early Pleistocene and replaced by the small-sized Xenocyon (previously Mececyon) during the earliest Middle Pleistocene. The latter is probably an anagenetic dwarf derived from the larger form of the preceding period. The change in body size of Xenocyon on Java over time is likely the effect of increased competition within the carnivore guild within the restricted boundaries of the island. Simultaneously with a pronounced body size shift, a dietary shift from large-sized prey to much smaller prey must have taken place in order to meet energetic constraints. The degree of endemism of terrestrial mammals of the earliest Middle Pleistocene horizon of the site Trinil, which has also yielded Homo erectus fossils, indicates that during this period, Java was marginally isolated which allowed for a corridor dispersal to the island with subsequent vicariance. The nature and degree of isolation may have been similar to that of Late Pleistocene Sicily, but of a longer duration, given the higher degree of dwarfism of the stegodon, antilope and canid. The following continentalisation enabled the invasion by mainland terrestrial mammals, as is seen in younger layers at Trinil, and eventually by Homo sapiens and Cuon in the Late Pleistocene / Holocene.

Environmental determination of body size in mammals: Rethinking ‘island dwarfism’ in the golden bandicoot

AbstractThere are several cases of insular animal species exhibiting dramatic differences in body size when compared with mainland counterparts. Such pronounced morphological changes can arise from divergent selection via differing resource availability, competition or predation pressure. Past studies have not been able to demonstrate a reversal of these morphological changes when populations are removed from their island situation. This study examines the body size response of populations of the Barrow Island ‘dwarf’ subspecies of golden bandicoot (Isoodon auratus barrowensis: Ramsay, 1887) following translocation to an island and mainland site within their former range. Skeletal and mass measurements, body condition and fecundity of released animals and their offspring were compared to data from the source population. When comparing bandicoots born at translocation sites to source populations, males were significantly larger in skeletal size and mass, females were also significantly larger and exhibited higher reproductive output (number, frequency and average mass of pouch young). These effects occurred in a gradient according to environmental conditions, where animals were smallest and least productive at the densely populated source site, larger and more productive on a nearby island, and largest and most productive at a mainland site with some nutritional supplementation. These changes in skeletal size, mass and fecundity took place in the first 1–4 generations (18 months post‐release), suggesting that the response is not explained by natural selection. We posit that the small size of golden bandicoots on Barrow Island (315.8 ± 4.2 g, this study, cf 569.4 ± 19.3 g, mainland) is not a genotypic response to selective pressures, but rather a reversible phenotypic response to more favourable environmental conditions. A reduction in competitive pressures appeared to allow bandicoots to grow to a larger size and mass, and allow greater reproductive output. Ecological processes relating to resource limitation appear to drive ‘island dwarfism’ in I. auratus, and may apply to other insular species with morphological differentiation.

Convergence in reduced body size, head size, and blood glucose in three island reptiles.

Many oceanic islands harbor diverse species that differ markedly from their mainland relatives with respect to morphology, behavior, and physiology. A particularly common morphological change exhibited by a wide range of species on islands worldwide involves either a reduction in body size, termed island dwarfism, or an increase in body size, termed island gigantism. While numerous instances of dwarfism and gigantism have been well documented, documentation of other morphological changes on islands remains limited. Furthermore, we lack a basic understanding of the physiological mechanisms that underlie these changes, and whether they are convergent. A major hypothesis for the repeated evolution of dwarfism posits selection for smaller, more efficient body sizes in the context of low resource availability. Under this hypothesis, we would expect the physiological mechanisms known to be downregulated in model organisms exhibiting small body sizes due to dietary restriction or artificial selection would also be downregulated in wild species exhibiting dwarfism on islands. We measured body size, relative head size, and circulating blood glucose in three species of reptiles—two snakes and one lizard—in the California Channel Islands relative to mainland populations. Collating data from 6 years of study, we found that relative to mainland population the island populations had smaller body size (i.e., island dwarfism), smaller head sizes relative to body size, and lower levels of blood glucose, although with some variation by sex and year. These findings suggest that the island populations of these three species have independently evolved convergent physiological changes (lower glucose set point) corresponding to convergent changes in morphology that are consistent with a scenario of reduced resource availability and/or changes in prey size on the islands. This provides a powerful system to further investigate ecological, physiological, and genetic variables to elucidate the mechanisms underlying convergent changes in life history on islands.

From Jumbo to Dumbo: Cranial Shape Changes in Elephants and Hippos During Phyletic Dwarfing

Members of the mammalian families Elephantidae and Hippopotamidae (extant and extinct elephants and hippos) include extinct dwarf species that display up to 98% decrease in body size compared to probable ancestral sources. In addition to differences in body mass, skulls of these species consistently display distinctive morphological changes, including major reduction of pneumatised areas in dwarf elephants and shortened muzzles in dwarf hippos. Here we build on previous studies of island dwarf species by conducting a geometric morphometric analysis of skull morphology and allometry in target taxa, living and extinct, and elaborate on the relation between skull size and body size. Our analysis indicates that skull size and body size within terrestrial placental mammals scale almost isometrically (PGLS major axis slope 0.906). Furthermore, skull shape in dwarf species differed from both their ancestors and the juveniles of extant species. In insular dwarf hippos, the skull was subject to considerable anatomical reorganisation in response to distinct selection pressures affecting early ontogeny (the “island syndrome”). By contrast, skull shape in adult insular dwarf elephants can be explained well by allometric effects; selection on size may thus have been the main driver of skull shape in dwarf elephants. We suggest that a tightly constrained growth trajectory, without major anatomical reorganization of the skull, allowed for flexible adaptations to changing environments and was one of the factors underlying the evolutionary success of insular dwarf elephants.

The terrestrial fauna of the Late Triassic Pant-y-ffynnon Quarry fissures, South Wales, UK and a new species of Clevosaurus (Lepidosauria: Rhynchocephalia)

Pant-y-ffynnon Quarry in South Wales yielded a rich cache of fossils in the early 1950s, including articulated specimens of new species (the small sauropodomorph dinosaur Pantydraco caducus and the crocodylomorph Terrestrisuchus gracilis), but no substantial study of the wider fauna of the Pant-y-ffynnon fissure systems has been published. Here, our overview of existing specimens, a few described but mostly undescribed, as well as freshly processed material, provides a comprehensive picture of the Pant-y-ffynnon palaeo-island of the Late Triassic. This was an island with a relatively impoverished fauna dominated by small clevosaurs (rhynchocephalians), including a new species, Clevosaurus cambrica, described here from a partially articulated specimen and isolated bones. The new species has a dental morphology that is intermediate between the Late Triassic Clevosaurus hudsoni, from Cromhall Quarry to the east, and the younger C. convallis from Pant Quarry to the west, suggesting adaptive radiation of clevosaurs in the palaeo-archipelago. The larger reptiles on the palaeo-island do not exceed 1.5 m in length, including a small carnivorous crocodylomorph, Terrestrisuchus, and a possible example of insular dwarfism in the basal dinosaur Pantydraco.

Disproving claims for small-bodied humans in the Palauan archipelago

Abstract