Johannes Müller

Museum für Naturkunde - Leibniz Institute for Research on Evolution and Biodiversity | MFN

Fluvial sediments of the middle Atbara River Valley, eastern Sudan, contain abundant vertebrate fossils and stone tools. Previous work described two sedimentary units, the Butana Bridge Synthem (BBS) and the Khashm El Girba Synthem (KGS), with three divisions each (BBS1-3 and KGS1-3, from bottom to top, respectively). ²³⁰Th/U dating on bivalve shel...

Recent comparative studies of billfishes (Istiophoridae and Xiphiidae) have provided evidence of differences in the form and function of the rostra (bill) among species. Here, we report the discovery of a new structure, lacuna rostralis, on the rostra of sailfish Istiophorus platypterus, which is absent on the rostra of swordfish Xiphias gladius, s...

Understanding the genomic basis of adaptation to different abiotic environments is important in the context of climate change and resulting short‐term environmental fluctuations. Using functional and comparative genomics approaches, we here investigated whether signatures of genomic adaptation to a set of environmental parameters are concentrated i...

Asian cobras (genus Naja ) are venomous snakes distributed from the Middle East to Southeast Asia. Because cobras often live near humans settlements, they are responsible for a large part of snakebite incidents and as such pose a challenge for public health systems. In the light of growing human populations, correctly mapping the present and future...

Since the 19th century, the addax (Addax nasomaculatus) has lost approximately 99% of its former range. Along with its close relatives, the blue antelope (Hippotragus leucophaeus) and the scimitar-horned oryx (Oryx dammah), the addax may be the third large African mammal species to go extinct in the wild in recent times. Despite this, the evolution...

Here we report on a new dyrosaurid from the latest Cretaceous Kababish Formation, Sudan, which was previously unknown to yield fossil macrovertebrates and had remained largely unstudied. The almost complete, partially articulated skeleton was recovered in situ near Jebel Abyad. The skeleton is almost 7 m in length and preserves an almost complete s...

Increasing artificial illumination during night has multifaceted effects on species. Moths are shown to be distracted and attracted by artificial light sources, leading to increased mortality through predation or exhaustion. Increased mortality can be expected to increase selection pressure on morphology, particularly those being functional in ligh...

The study of deep-time ecological dynamics has the ability to inform conservation decisions by anticipating the behavior of ecosystems millions of years into the future. Using network analysis and an exceptional fossil dataset spanning the past 21 million years, we show that mammalian ecological assemblages undergo long periods of functional stasis...

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...

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 gener...

Based on its mandibular gland secretion, the earless monitor lizard, Lanthanotus borneensis, has been considered a venomous animal like other members of the Toxicofera group, including Heloderma. In the present study, the gland structure and teeth of L. borneensis were examined by micro-tomography (μCT) and scanning electron microscopy (SEM), respe...

𝗕𝗮𝗰𝗸𝗴𝗿𝗼𝘂𝗻𝗱. The study of convergently acquired adaptations allows fundamental insight into life's evolutionary history. Within lepidosaur reptiles – i.e., lizards, tuatara, and snakes – a fully fossorial ('burrowing') lifestyle has independently evolved in most major clades. However, despite their con-sistent use of the skull as a digging tool, cra...

Despite growing pressure on biodiversity deriving from increasing anthropogenic disturbances, some species successfully persist in altered ecosystems. However, these species' characteristics and thresholds, as well as the environmental frame behind that process are usually unknown. We collected data on body size, fluctuating asymmetry (FA), as well...

The repeated evolution of convergent or analogous traits is often used as evidence for adaptive evolution. Squamate reptiles show a high degree of convergence in a variety of morphological traits; however, the evolutionary mechanisms driving these patterns are not fully understood. Here, we investigate the evolution of tail spines, a trait that evo...

Natural history museums are unique spaces for interdisciplinary research and educational innovation. Through extensive exhibits and public programming and by hosting rich communities of amateurs, students, and researchers at all stages of their careers, they can provide a place-based window to focus on integration of science and discovery, as well...

Increasing anthropogenic environmental impacts lead to rapid transitions of ecosystems and species. Species persisting in changing environments may respond to changes by altering phenotypic traits across space and/or time. Here we tested whether the frequencies of three color morphs in the ground beetle Harpalus affinis differed across spatial and...

Linking morphological differences in foraging adaptations to prey choice and feeding strategies has provided major evolutionary insights across taxa. Here, we combine behavioural and morphological approaches to explore and compare the role of the rostrum (bill) and micro-teeth in the feeding behaviour of sailfish (Istiophorus platypterus) and strip...

The acquisition of a fossorial lifestyle in squamates provides an excellent framework to study convergent evolution. In that context, the gross morphology of the skull in these head-first-burrowers has been the subject of several studies. However, to our knowledge, the inner structure of the cranial bones has never been quantified. We here test whe...

The acquisition of a fossorial lifestyle in squamates provides an excellent framework to study convergent evolution. In that context, the gross morphology of the skull in these head-first-burrowers has been the subject of several studies. However, to our knowledge, the inner structure of the cranial bones has never been quantified. We here test whe...

Background The evolution of elongated body forms in tetrapods has a strong influence on the musculoskeletal system, including the reduction of pelvic and pectoral girdles, as well as the limbs. However, despite extensive research in this area it still remains unknown how muscles within and around bony girdles are affected by these reductions. Here...

Fossoriality has been acquired repeatedly in the evolutionary history of squamates (e.g., worm lizards, sand skinks, hog-nosed snakes). Related to this case of convergent evolution, the gross morphology of the skull in the corresponding fossorial clades has been subject of numerous studies. Indeed, these clades mostly comprise head-first-burrowers,...

Global change has complex eco-evolutionary consequences for organisms and ecosystems, but related concepts (e.g., novel ecosystems) do not cover their full range. Here we propose an umbrella concept of “ecological novelty” comprising (1) a site-specific and (2) an organismcentered, eco-evolutionary perspective. Under this umbrella, complementary op...

Climatic conditions changing over time and space shape the evolution of organisms at multiple levels, including temperate lizards in the family Lacertidae. Here we reconstruct a dated phylogenetic tree of 262 lacertid species based on a supermatrix relying on novel phylogenomic datasets and fossil calibrations. Diversification of lacertids was acco...

Understanding the genomic basis of adaptation to different abiotic environments is important for understanding organismal responses to current short-term environmental fluctuations. Using functional and comparative genomics approaches, we here investigated whether genomic adaptation to a set of environmental parameters is contingent across vertebra...

Vertebrate ecology has been successfully inferred from bone microstructure in the past, but a systematic approach to quantify differences of the inner bone structure in the skull of squamate reptiles, i.e., lizards and snakes, has never been undertaken. In head-first-burrowing squamates, for example, the cranium is the structure exposed to the grea...

Our current understanding of form and function of the structures employed for vocalization in Testudines remains notably limited. To gain insight into their possible interactions, we carried out μCT-scans on the larynx of Testudo horsfieldii (Testudinidae) and Emys orbicularis (Emydidae), which serve as examples of the two turtle clades with the gr...

Factors intrinsic and extrinsic to organisms dictate the course of morphological evolution but are seldom considered together in comparative analyses. Among vertebrates, squamates (lizards and snakes) exhibit remarkable morphological and developmental variations that parallel their incredible ecological spectrum. However, this exceptional diversity...

Rhynchosauria is a group of archosauromorph reptiles abundant in terrestrial ecosystems of the Middle Triassic. Mesosuchus is one of the earliest and basalmost rhynchosaurs, playing an important role not only for the understanding of the evolution of the group as a whole, but also of archosauromorphs in general. The braincase of Mesosuchus has been...

Natural history museums are unique spaces for interdisciplinary research and for educational innovation. Through extensive exhibits and public programming and by hosting rich communities of amateurs, students, and researchers at all stages of their careers, they provide a place-based window to focus on integration of science and discovery, as well...

Natural history museums are unique spaces for interdisciplinary research and for educational innovation. Through extensive exhibits and public programming and by hosting rich communities of amateurs, students, and researchers at all stages of their careers, they provide a place-based window to focus on integration of science and discovery, as well...

Developmental instability provides a powerful monitoring tool to detect threats prior to population declines. Consequently, assessing the level of developmental instability by measuring fluctuating asymmetry (FA) of bilaterally symmetrical traits in association with environmental stress has become increasingly attractive. However, many studies fail...

[This corrects the article DOI: 10.1371/journal.pone.0069264.].

Worm lizards, or amphisbaenians, of the genus Blanus are found in various countries around the Mediterranean Sea. In addition to four extinct species, seven extant taxa are currently recognized. Here, we present the first comparative analysis of the cranial osteology of Blanus including all extant species. The results of this analysis show a homoge...

Despite extensive research on ecological community compositions, general patterns across large-scale environmental gradients have remained unclear. A widely used explanatory model is the stress dominance hypothesis (SDH), predicting that the relative influence of environmental filtering is greater in stressful habitats while competition is more imp...

We describe the first record of a fossil gekkotan from the Late Oligocene Nsungwe Formation in the Rukwa Rift Basin, Tanzania. The specimen consists of an almost complete maxilla containing 23 tooth positions, with 10 teeth still in place. Typical gekkotan features include the tall facial process along with a posteriorly sloping angle, and the pres...

The squamate fossil record from Kanapoi reveals generic to higher-order similarities with modern East African herpetofaunas. The record is derived from surface collection and screen washing, and consists primarily of isolated vertebrae with a few maxillary and mandibular elements. The most abundant remains are vertebrae of large-bodied Python that...

Sensory perception is of crucial importance for animals to interact with their biotic and abiotic environment. In amniotes, the clade including modern mammals (Synapsida), modern reptiles (Reptilia), and their fossil relatives, the evolution of sensory perception took place in a stepwise manner after amniotes appeared in the Carboniferous. Fossil e...

The anatomy of African lacertid lizards (Lacertidae: Eremiadini) is poorly known, which has hindered a better understanding of their evolutionary relationships. This applies especially to the East African clade, which includes the genera Nucras, Latastia, Philochortus, Pseuderemias and Heliobolus. We present a detailed description of the skull oste...

The US and Mexico share a common history in many areas, including language and culture. They face ecological changes due to the increased frequency and severity of droughts and rising energy demands; trends that entail economic costs for both nations and major implications for human well being. We describe an ongoing effort by the Environment Worki...

The ecological origin of snakes remains amongst the most controversial topics in evolution, with three competing hypotheses: fossorial; marine; or terrestrial. Here we use a geometric morphometric approach integrating ecological, phylogenetic, paleontological, and developmental data for building models of skull shape and size evolution and developm...

The best-preserved material of Dracaenosaurus croizeti, an almost complete and previously unpublished skull with a few associated postcranial bones (stylopodium, zeugopodium, and cervical vertebra), is described. The material comes from the locality of Cournon, a late Oligocene site in south-central France. Micro-computed tomography applied to this...

Knowledge of the thermal ecology of a species can improve model predictions for temperature-induced population collapse, which in light of climate change is increasingly important for species with limited distributions. Here, we use a multi-faceted approach to quantify and integrate the thermal ecology, properties of the thermal habitat, and past a...

During early development of turtles and other amniotes, the parabasisphenoid, or basisphenoid s.l., is formed by at least two centers of ossification: the endochondral basisphenoid s.s. and the dermal parasphenoid. This fusion is usually so dramatic that the two elements cannot be distinguished from each other in the adult stage. Here we describe t...

It is generally assumed that ectothermic vertebrates show a reversed Bergmann's cline, but several studies suggest the opposite for turtles. Here, we assess this issue using the widely distributed European pond turtle (Emys orbicularis), which displays strong geographic size variation. We tested carapace lengths of more than 2000 individuals from t...

Within the genus Pedioplanis the two basal species P. laticeps and P. burchelli are phenotypically similar. In this study we examine material of both species to determine diagnostic characters and we revise the distribution of Pedioplanis laticeps. For this we used data from museum collections, literature records, as well as results from our own su...