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"Tuatara."
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Clade-wide variation in bite-force performance is determined primarily by size, not ecology
Performance traits are tightly linked to the fitness of organisms. However, because studies of variation in performance traits generally focus on just one or several closely related species, we are unable to draw broader conclusions about how and why these traits vary across clades. One important performance trait related to many aspects of an animal’s life history is bite-force. Here, we use a clade-wide phylogenetic comparative approach to investigate relationships between size, head dimensions and bite-force among lizards and tuatara (lepidosaurs), using the largest bite-force dataset collated to date for any taxonomic group. We test four predictions: that bite-force will be greater in larger species, and for a given body size, bite-force will be greatest in species with acrodont tooth attachment, herbivorous diets, and non-burrowing habits. We show that bite-force is strongly related to body and head size across lepidosaurs and, as predicted, larger species have the greatest bite-forces. Contrary to our other predictions, tooth attachment, diet and habit have little predictive power when accounting for size. Herbivores bite more forcefully simply because they are larger. Our results also highlight priorities for future sampling to further enhance our understanding of broader evolutionary patterns.
Journal Article
100-year-old tuataras!
Introduces the reptile called the tuatara, which is found only in New Zealand and is adapted from many different kinds of animals, including amphibians, reptiles, and fish.
Book
Integration of molecules and new fossils supports a Triassic origin for Lepidosauria (lizards, snakes, and tuatara)
Background
Lepidosauria (lizards, snakes, tuatara) is a globally distributed and ecologically important group of over 9,000 reptile species. The earliest fossil records are currently restricted to the Late Triassic and often dated to 227 million years ago (Mya). As these early records include taxa that are relatively derived in their morphology (e.g.
Brachyrhinodon
), an earlier unknown history of Lepidosauria is implied. However, molecular age estimates for Lepidosauria have been problematic; dates for the most recent common ancestor of all lepidosaurs range between approximately 226 and 289 Mya whereas estimates for crown-group Squamata (lizards and snakes) vary more dramatically: 179 to 294 Mya. This uncertainty restricts inferences regarding the patterns of diversification and evolution of Lepidosauria as a whole.
Results
Here we report on a rhynchocephalian fossil from the Middle Triassic of Germany (Vellberg) that represents the oldest known record of a lepidosaur from anywhere in the world. Reliably dated to 238–240 Mya, this material is about 12 million years older than previously known lepidosaur records and is older than some but not all molecular clock estimates for the origin of lepidosaurs. Using RAG1 sequence data from 76 extant taxa and the new fossil specimens two of several calibrations, we estimate that the most recent common ancestor of Lepidosauria lived at least 242 Mya (238–249.5), and crown-group Squamata originated around 193 Mya (176–213).
Conclusion
A Early/Middle Triassic date for the origin of Lepidosauria disagrees with previous estimates deep within the Permian and suggests the group evolved as part of the faunal recovery after the end-Permain mass extinction as the climate became more humid. Our origin time for crown-group Squamata coincides with shifts towards warmer climates and dramatic changes in fauna and flora. Most major subclades within Squamata originated in the Cretaceous postdating major continental fragmentation. The Vellberg fossil locality is expected to become an important resource for providing a more balanced picture of the Triassic and for bridging gaps in the fossil record of several other major vertebrate groups.
Journal Article
Initial collection, characterization, and storage of tuatara (Sphenodon punctatus) sperm offers insight into their unique reproductive system
Successful reproduction is critical to the persistence of at-risk species; however, reproductive characteristics are understudied in many wild species. New Zealand’s endemic tuatara ( Sphenodon punctatus) , the sole surviving member of the reptile order Rhynchocephalia, is restricted to 10% of its historic range. To complement ongoing conservation efforts, we collected and characterized mature sperm from male tuatara for the first time. Semen collected both during mating and from urine after courting contained motile sperm and had the potential for a very high percentage of viable sperm cells (98%). Scanning electron microscopy revealed a filiform sperm cell with distinct divisions: head, midpiece, tail, and reduced end piece. Finally, our initial curvilinear velocity estimates for tuatara sperm are 2–4 times faster than any previously studied reptile. Further work is needed to examine these trends at a larger scale; however, this research provides valuable information regarding reproduction in this basal reptile.
Journal Article
Tuatara genome reveals diverse insights into a remarkable reptile
The genome sequence of an unusual reptile called the tuatara sheds light on the species’ evolution and on conservation strategies. The work is a model of current best practice for collaborating with Indigenous communities.
Whole-genome sequence for the tuatara.
Journal Article
Mammal-related Cryptosporidium infections in endemic reptiles of New Zealand
New Zealand’s endemic reptile fauna is highly threatened and pathogens causing infectious diseases may be a significant risk to already endangered species. Here, we investigate
Cryptosporidium
infection in captive endemic New Zealand reptiles. We found two mammal-related
Cryptosporidium
species (
C. hominis
and
C. parvum
) and six subtypes from three gp60 families (Ib, Ig and IIa) in 12 individuals of captive endemic Tuatara, Otago and Grand skinks, and Jewelled and Rough geckos.
Cryptosporidium serpentis
was identified in two Jewelled geckos using 18S. In New Zealand,
C. hominis
and
C. parvum
are associated with infections in humans and introduced domestic animals but have also been recently found in wildlife. Our finding of
Cryptosporidium
infection in endemic reptiles can help inform strategies to monitor the conservation of species and manage potential introductions of pathogens to
in-situ
and
ex-situ
populations.
Journal Article
The first recorded interaction between two species separated for centuries suggests they were ecological competitors
Presents and comments on video footage that, for the first time, captures an interaction between two species separated for centuries due to human disturbance, but that are now being reconnected via translocations : little spotted kiwi (LSK) (Apteryx owenii) and tuatara (Sphenodon punctatus). Source: National Library of New Zealand Te Puna Matauranga o Aotearoa, licensed by the Department of Internal Affairs for re-use under the Creative Commons Attribution 3.0 New Zealand Licence.
Journal Article
Understanding Publication Bias in Reintroduction Biology by Assessing Translocations of New Zealand's Herpetofauna
The intentional translocation of animals is an important tool for species conservation and ecosystem restoration, but reported success rates are low, particularly for threatened and endangered species. Publication bias further distorts success rates because the results of successful translocations may be more likely to be published than failed translocations. We conducted the first comprehensive review of all published and unpublished translocations of herpetofauna in New Zealand to assess publication bias. Of 74 translocations of 29 species in 25 years, 35 have been reported in the published literature, and the outcomes of 12 have been published. Using a traditional definition of success, publication bias resulted in a gross overestimate of translocation success rates (41.7% and 8.1% for published and all translocations, respectively), but bias against failed translocations was minimal (8.3% and 6.8%, respectively). Publication bias against translocations with uncertain outcomes, the vast majority of projects, was also strong (50.0% and 85.1% for published and all translocations, respectively). Recent translocations were less likely to be published than older translocations. The reasons behind translocations were related to publication. A greater percentage of translocations for conservation and research were published (63.3% and 40.0%, respectively) than translocations for mitigation during land development (10.0%). Translocations conducted in collaboration with a university were more frequently published (82.7% and 24.4%, respectively). To account for some of this publication bias, we reassessed the outcome of each translocation using a standardized definition of success, which takes into consideration the species’ life history and the time since release. Our standardized definition of translocation success provided a more accurate summary of success rates and allows for a more rigorous evaluation of the causes of translocation success and failure in large‐scale reviews. Entendiendo el Sesgo de Publicaciones en la Biología de la Reintroducción Mediante el Estudio de Traslocaciones de la Herpetofauna de Nueva Zelanda
Journal Article
Season, Body Condition and Developmental Stage Influence the Gut Microbiota of the Sole Living Rhynchocephalian Reptile (Sphenodon punctatus)
Seasonality plays a crucial role for many species, especially reptiles. In multiple reptile species, seasonality has been linked to shifts in the gut microbiota, influenced by factors, such as ambient temperature, food availability and shifting host function across different seasons. We tested whether the tuatara, an endemic New Zealand reptile and the sole extant member of the order Rhynchocephalia, maintains a stable gut microbiota over 2 years of sampling across three seasons (summer, autumn, spring) or if the dominant bacterial community varies with season. We found that community diversity changed significantly seasonally, with the most diverse gut community found in the spring. We also found that season significantly influenced beta‐diversity, as did tuatara developmental stage, tuatara body condition and tick abundance. However, there was little evidence for a recurring seasonal bacterial assemblage in 2024 compared with 2023. For tuatara where the same individual was resampled over multiple seasons, bacterial community composition appeared to be most correlated with the time of sampling, with closer temporal samples more similar to one another than samples taken further apart, which was also seen in the significance of the sampling period as a factor explaining variation across all tuatara. We identified bacterial genera that significantly increased or decreased in each season. Despite notable shifts among seasons, particularly in autumn, the tuatara gut microbiota exhibits remarkable persistence over time, including within individuals. Seasonality plays a crucial role for many species, especially reptiles. We tested whether the tuatara, an endemic New Zealand reptile and the sole extant member of the order Rhynchocephalia, maintains a stable gut microbiota over 2 years of sampling across three seasons (summer, autumn and spring) or if the dominant bacterial community varies with season. We found that community diversity changed significantly seasonally, with the most diverse gut community found in the spring; that season significantly influenced beta‐diversity, as did tuatara life stage, tuatara body condition and tick abundance. However, there was little evidence for a reoccurring seasonal bacterial assemblage in 2024 compared with 2023.
Journal Article