Life restoration of a group of giant azhdarchids, Quetzalcoatlus northropi, foraging on a Cretaceous fern prairie.
A juvenile titanosaur has been procured by one pterosaur, while the others stalk through the scrub in search of small vertebrates and other foodstuffs.
A juvenile titanosaur has been procured by one pterosaur, while the others stalk through the scrub in search of small vertebrates and other foodstuffs.
New research by scientists led by the University of Leicester has filled in another of those gaps much sought after by creationists as somewhere to fit their ever-shrinking little god. The gap was in our understanding of how and when the pterosaurs evolved to their gigantic size from their small beginnings.
Because this took place over the almost 190 million years that pterosaurs were around before going extinct, along with the dinosaurs, 66 million years ago, most creationists will probably have ignored it because it all happened so long before 'Creation Week'. Any reference to gaps in the fossil record that long ago will mean simultaneously holding two mutually exclusive views about the age of Earth, with all the painful cognitive dissonance that entails, so creationists frauds will most likely have kept quiet about it if they were even aware of it.
Tell me all about the pterosaurs and their evolution, please. Pterosaurs were flying reptiles that lived during the Mesozoic Era, from the Late Triassic to the end of the Cretaceous period (around 228 to 66 million years ago). They were the first vertebrates to achieve powered flight and are among the most fascinating creatures of the age of dinosaurs. Their evolutionary history and biology reveal an incredible story of adaptation, radiation, and eventual extinction.The team of palaeontologists have just published their findings, open access, in the Cell Press journal, Current Biology and announced it in a Leicester University news release:
Origins and Early Evolution
Pterosaurs belong to a group of reptiles known as archosaurs, which also includes dinosaurs and crocodiles. Their evolutionary origins remain somewhat mysterious, but they are believed to have evolved from small, agile reptiles closely related to early dinosaurs. Pterosaurs first appeared in the Late Triassic period, roughly 228 million years ago, although fossils from this period are rare. The earliest pterosaurs were relatively small, with wingspans of around 1 meter (3 feet), and were likely insectivores.
The key evolutionary adaptation of pterosaurs was their wings. Unlike birds or bats, whose wings are formed primarily by modified forelimbs, pterosaur wings were supported by a highly elongated fourth finger, with a membrane of skin, muscle, and other tissues extending to the sides of the body. Their bone structure was also highly specialized, with lightweight but strong, hollow bones, allowing for efficient flight.
Major Groups of Pterosaurs
Pterosaurs evolved into a wide variety of forms, with two main subgroups:
- Rhamphorhynchoids (basal pterosaurs):
- These were the early pterosaurs that lived during the Triassic and Jurassic periods. They had long tails, often with diamond-shaped tips, and their wings were relatively short compared to later pterosaurs. They were generally smaller, with many species having wingspans between 1 to 3 meters (3 to 10 feet).
- Examples: Rhamphorhynchus, Dimorphodon.
- Pterodactyloids (advanced pterosaurs):
- This group emerged in the Late Jurassic and dominated the skies until the end of the Cretaceous. Pterodactyloids had shorter tails and elongated metacarpals (hand bones), giving them larger wings. They were generally larger than their predecessors, and some species grew to enormous sizes. Their diversity was remarkable, ranging from small forms with 1-meter wingspans to giant species with wingspans exceeding 10 meters (33 feet).
- Examples: Pteranodon, Quetzalcoatlus, Anhanguera.
Physical Adaptations and Flight
Pterosaur wings were a marvel of evolutionary engineering. The wing membrane, or patagium, was divided into several sections. The largest portion stretched between the elongated fourth finger and the body, while smaller membranes connected the legs and possibly the tail in some species. This structure allowed for sophisticated control of flight dynamics. Some pterosaurs also had stiffened fibers, known as actinofibrils, within their wing membranes to help control tension and wing shape during flight.
The evolution of pterosaurs' body structure was similarly optimized for flight. Their bodies were streamlined, with small torsos and large, lightweight heads. Pterosaurs also had keeled breastbones, which provided anchorage for their large flight muscles, akin to the structure seen in modern birds.
Ecological Roles and Diversity
Pterosaurs were incredibly diverse in terms of size, feeding habits, and ecological roles. Some species were piscivores (fish-eaters), while others specialized in catching insects, preying on small terrestrial animals, or scavenging. Their beaks, teeth, and other cranial features varied widely to match their diets.
- Piscivorous pterosaurs like Pteranodon and Anhanguera had long, toothless beaks or conical teeth for catching fish. These species likely spent much of their time near coastal environments.
- Insectivorous pterosaurs, such as some smaller rhamphorhynchoids, had sharp teeth and agile bodies for catching flying insects.
- Large scavengers or carnivores, like Quetzalcoatlus, one of the largest known pterosaurs, may have fed on carrion or hunted small dinosaurs.
Gigantism in Pterosaurs
Some of the most astonishing aspects of pterosaur evolution are the gigantic species that emerged in the Late Cretaceous. Quetzalcoatlus, with a wingspan of around 10 to 11 meters (33 to 36 feet), was one of the largest known flying animals of all time. Despite their size, these giants were likely capable of flight due to their lightweight, hollow bones, and highly efficient flight muscles. Some researchers suggest that the largest pterosaurs may have used thermal currents to soar over long distances, much like modern albatrosses.
Evolution of Head Crests
Many advanced pterosaurs, particularly in the Pterodactyloid group, had elaborate head crests. These crests varied greatly in size and shape, with some species having massive, brightly colored crests that may have served for display or sexual selection, similar to the plumage of modern birds. The crests were often made of bone and sometimes supported soft tissue extensions that increased their visual impact.
Extinction of Pterosaurs
Pterosaurs, along with non-avian dinosaurs, went extinct at the end of the Cretaceous period, about 66 million years ago. The leading hypothesis for this mass extinction is the impact of a large asteroid, which caused dramatic changes in climate and ecosystems. It is believed that the environmental fallout from this event led to the collapse of many ecosystems, including those that supported pterosaurs. While some smaller bird-like dinosaurs survived and gave rise to modern birds, no pterosaurs made it past this extinction event.
Pterosaur Fossil Record and Discovery
Pterosaur fossils are relatively rare compared to other prehistoric reptiles because their delicate, hollow bones were less likely to fossilize well. However, significant fossil finds have been made in places like Germany (Solnhofen limestone), China (Liaoning Province), and Brazil (Santana Formation). These fossils have provided incredible insight into pterosaur anatomy, life history, and diversity.
Pterosaurs vs. Birds
One common misconception is that pterosaurs were the ancestors of birds. In reality, pterosaurs and birds evolved independently from different groups of archosaurs. Birds descended from small theropod dinosaurs, while pterosaurs represent a distinct evolutionary branch that developed flight separately. Despite their differences, both groups adapted in remarkable ways to life in the air, demonstrating convergent evolution in their flight abilities.
Significance in Evolutionary History
Pterosaurs hold a special place in evolutionary history as the first vertebrates to evolve powered flight. Their success across diverse habitats and their adaptations, such as gigantism and head crests, reflect the wide range of evolutionary experiments that took place during the Mesozoic Era. Their extinction left a niche in the skies that birds and, later, bats would eventually fill.
In summary, pterosaurs were a diverse and remarkable group of flying reptiles that evolved sophisticated adaptations for flight, exploited a wide range of ecological roles, and achieved incredible diversity in size and form. Their extinction marked the end of an era, but their legacy continues to fascinate scientists and the public alike.
Pterosaurs needed feet on the ground to become giants
The evolutionary adaptations that allowed ancient pterosaurs to grow to enormous sizes have been pinpointed for the first time by palaeontologists in the Centre for Palaeobiology and Biosphere Evolution at the University of Leicester.
The discovery revealed a surprising twist – the ability to walk efficiently on the ground played a crucial role in determining how large the biggest flying animals could grow, with some reaching wingspans of up to 10 metres.
In a new study published today (4 October) in Current Biology, a team of researchers led by the University of Leicester examined the hands and feet of pterosaurs from around the world and across their entire evolutionary history.
They uncovered a surprising level of variation similar to that seen across living birds. This discovery indicates that pterosaurs were not confined to a life in the skies but were also adapted to a wide range of terrestrial lifestyles, from tree-climbing in early species to more ground-based lifestyles in later ones.
The evolution of pterosaurs, the first true flying vertebrates, showcases some of the most remarkable adaptations in the history of life. While these creatures are best known for their ability to soar through the prehistoric skies of the Mesozoic era (252-66 million years ago), a new study has revealed a surprisingly high degree of diversity in where and how pterosaurs lived when they were not airborne.
Lead author Robert Smyth, a doctoral researcher in the in the Centre for Palaeobiology and Biosphere Evolution (School of Geography, Geology and the Environment at the University of Leicester), explained:
Early pterosaurs were highly specialised for climbing, with extreme modifications in their hands and feet, similar to those found in climbing lizards and birds like woodpeckers today. Clinging to vertical surfaces by your fingertips for long periods is hard work — it’s a lot easier for small, lightweight animals.
Dr. Robert S.H. Smyth, lead author
Centre for Palaeobiology & Biosphere Evolution
School of Geography, Geology, and the Environment
University of Leicester, Leicester, UK.
These early pterosaurs were likely restricted to arboreal habitats and consequently, small body sizes. However, a major evolutionary shift occurred during the Middle Jurassic period, when pterosaur hands and feet changed to look much more like those of ground-dwelling animals. These adaptations to ground-based movement opened up new ecological opportunities, leading to a wide variety of feeding strategies. Freedom from the size constraints imposed by vertical living allowed some pterosaurs to evolve to gigantic size with wingspans of up to 10 metres.
In early pterosaurs the hind limbs were connected by a flight membrane which severely impeded walking and running. In later, more advanced pterosaurs, this membrane became separated along the midline, allowing each hind limb to move independently. This was a key innovation that, combined with changes to their hands and feet, greatly improved pterosaurs’ mobility on the ground. Freed from the constraints of climbing, these later pterosaurs could grow to enormous sizes, with some species becoming true giants of the Mesozoic.
Dr David M. Unwin, co-author
Centre for Palaeobiology & Biosphere Evolution
School of Museum Studies
University of Leicester, Leicester, UK.
The details of the hands and feet are a clear giveaway. In early pterosaurs, the bones at the base of the fingers and toes were relatively short, while those farther from the body were greatly elongated, ending in large, curved claws – together these modifications resulted in a powerful grip – ideal for climbing. By contrast, later, more advanced pterosaurs showed the opposite pattern: the bones at the base of their fingers and toes were much longer, while those closer to the tips were shorter. Their claws were also flatter and less curved, suggesting they were better adapted for walking rather than climbing.
These findings underscore the need to examine all aspects of pterosaur locomotion, not just flight, to fully understand their evolution. That pterosaurs could fly is only one part of their story. By exploring how they lived in the trees or on the ground, we can begin to understand the roles that they played in ancient ecosystems.
Dr. Robert S.H. Smyth.
When pterosaurs arrived on the ground, it was already inhabited by a wide range of animals, including dinosaurs and many other reptiles. Pterosaurs cleverly avoided competition with these established groups by exploiting ecological niches that required both flying and walking abilities. This resulted in some bizarre feeding strategies such as evolving hundreds of fine, needle-like teeth that were used for filter-feeding. This remarkable feature, resembling the feeding method of modern flamingos, emerged at least 120 million years before the first flamingos evolved.
Publication:Hand and foot morphology maps invasion of terrestrial environments by pterosaurs in the mid-Mesozoic will be published in Current Biology,
DOI: 10.1016/j.cub.2024.09.014
HighlightsThe authors of Genesis were as unaware of dinosaurs and pterosaurs as they were of elephants, giraffes and penguins, or anything outside their small part of the Middle East or anything before their folk memory, so naturally they included nothing about them in their campfire tales and invented histories. This is how we can tell the Bible could not have been written by an omniscient entity, real or supernatural. The most notable things about the tales in it are the ignorance and scientific illiteracy of the authors.
- The hands and feet of pterosaurs were adapted to a broad range of locomotor ecologies.
- Early pterosaurs had a scansorial mode of life, which restricted maximum body size.
- Anatomical changes in later pterosaurs led to more effective terrestrial ability.
- Invasion of terrestrial habitats facilitated diverse feeding ecologies and gigantism.
Summary
Pterosaurs, the first true flying vertebrates, played a crucial role in Mesozoic terrestrial ecosystems. However, our understanding of their ability to move around on the ground and, more broadly, their terrestrial paleoecology remains limited. Here, we demonstrate an unexpectedly high degree of variation in the hands and feet of pterosaurs, comparable with that observed in extant birds. This suggests that pterosaurs were adapted to a remarkably broad range of non-aerial locomotor ecologies. Small, early, long-tailed pterosaurs (non-pterodactyliforms) exhibit extreme modifications in their hand and foot proportions indicative of climbing lifestyles. By contrast, the hands and feet of later, short-tailed pterosaurs (pterodactyliforms) typically exhibit morphologies consistent with more ground-based locomotor ecologies. These changes in proportions correlate with other modifications to pterosaur anatomy, critically, the separation along the midline of the flight membrane (cruropatagium) that linked the hindlimbs, enabling a much more effective locomotory ability on the ground. Together, these changes map a significant event in tetrapod evolution: a mid-Mesozoic colonization of terrestrial environments by short-tailed pterosaurs. This transition to predominantly ground-based locomotor ecologies did not occur as a single event coinciding with the origin of short-tailed forms but evolved independently within each of the four principal radiations: euctenochasmatians, ornithocheiroids, dsungaripteroids, and azhdarchoids. Invasion of terrestrial environments by pterosaurs facilitated the evolution of a wide range of novel feeding ecologies, while the freedom from limitations imposed by climbing permitted an increase in body size, ultimately enabling the evolution of gigantism in multiple lineages.
Introduction
Pterosaurs were a key constituent of Earth’s terrestrial biotas from the Late Triassic to the end of the Cretaceous (227–66 million years ago [mya]).1,2,3 The first vertebrates to achieve active flapping flight, pterosaurs were anatomically and ecologically diverse and distributed worldwide throughout much of their history. Traditionally, pterosaurs have been divided into two groups: “rhamphorhynchoids,” a paraphyletic grade characterized by several plesiomorphic features, including a long tail (Figures 1A and 1C), and pterodactyloids, a derived clade with a highly reduced tail (Figures 1B and 1C). Increasingly sophisticated phylogenetic analyses4,5,6 and recent additions to the fossil record of species such as Douzhanopterus zhengi7 and Propterodactylus frankerlae,8,9 posited as “transitional” forms, mean that these terms are no longer sufficient to describe the morphological transformations that underpin pterosaur evolutionary history. Consequently, here we have adopted two additional terms that permit more precise characterization of pterosaur morphological variation, phylogeny, and evolution. Non-pterodactyliforms, a paraphyletic grouping of early pterosaurs (Figure 1D), thrived during the early Mesozoic (Late Triassic to Late Jurassic).4 This grade group is united by a bauplan comprising a more typically archosaurian skull morphology compared with later pterosaurs, a short neck, an elongated tail, and a well-developed fifth pedal digit that supported a membranous wing panel stretching between the hindlimbs—the cruropatagium (Figures 1A and 1C). Pterodactyliform pterosaurs (Propterodactylus + Douzhanopterus + pterodactyloids) are distinguished by large, extensively pneumatized skulls, elongated necks, short tails, and reduced fifth pedal digits. These features become even more pronounced among the pterodactyloids, which also develop a bifurcated and significantly reduced cruropatagium (Figures 1B and 1C). Pterodactyloids were the most successful group of pterosaurs in the later part of the Mesozoic (Late Jurassic and Cretaceous).Although advances have been made in understanding pterosaur skeletal and soft tissue anatomy,1,2,3 phylogeny,10 flight,11,12 and ontogeny,13 their non-aerial locomotor abilities and ecologies are poorly known. It is generally accepted that grounded pterosaurs were quadrupedal, with a functional tridactyl digitigrade manus and functional tetradactyl plantigrade pedes.14 Uniquely among flying animals, manual digit IV and pedal digit V were exapted from their original functions to become flight structures.15,16 However, attempts to identify the terrestrial capabilities and feeding ecologies of specific clades have created much controversy,17,18 and the terrestrial abilities of both non-pterodactyliforms17 and pterodactyliforms are highly debated.19,20,21 Despite these controversies, pterosaur hand and foot morphologies have been largely overlooked,14,22,23 with little documentation of how these vary across Pterosauria. This oversight is particularly remarkable considering the fundamental role they play in locomotion. Comparative analysis of manus and pes morphologies could provide important new insights into the ecological roles of pterosaurs within Mesozoic biotas and how this impacted on contemporaneous vertebrate groups, among them a plethora of other volant and gliding Mesozoic amniote groups, including birds.24,25,26
Figure 1 Comparison of autopodial and other anatomical differences between non-pterodactyliform (scaphognathine) and pterodactyliform pterosaurs (derived ctenochasmatoid)
- (A) Paleoart reconstruction of the non-pterodactyliform Scaphognathus crassirostris (Upper Jurassic) in scansorial mode, with autopodia characterized by short proximal elements and elongated distal elements.
- (B) Paleoart reconstruction of the pterodactyliform Balaenognathus maeuseri(Upper Jurassic) in terrestrial mode, with autopodia characterized by elongated proximal elements and shortened distal elements.
- (C) Reconstructions of Scaphognathus (left) and Balaenognathus (right) in dorsal view indicating the principal flight surfaces.
- (D) Simplified pterosaur phylogeny indicating the principal taxonomic groups used in this study. Abbreviations: bp, brachiopatagium; cp, cruropatagium; pp, propatagium.
Paleoart by Rudolf Hima.
Hands and feet—or autopodia—perform a wide range of functions, facilitating locomotion across various modes, including walking, running, jumping, burrowing, swimming, climbing, and flying.27 Because the functions of autopodia are so closely tied to specific locomotor modes and ecologies of organisms, the degree to which locomotor modes influence their morphology is often greater than in the rest of the appendicular skeleton.28,29,30,31 Numerous paleontological studies have employed comparative datasets of extant tetrapod autopodia to reconstruct the locomotory modes of extinct animals.32,33,34,35,36 Until now, the pterosaur autopodial skeleton (excluding the wing elements) has contributed little to our understanding of their non-aerial locomotor ecology, primarily due to lack of available morphometric data for manual and pedal elements.
In this study, we compiled a comprehensive morphometric dataset for the manus and pes that includes ∼64 taxa, representing 18/20 principal pterosaur groups and ranging across their entire history, from the Upper Triassic to Upper Cretaceous (supplemental information). The dataset consists, primarily, of length measurements of phalanges forming digits I–III of the manus (the “claw digits”) and pedal rays I–IV of the pes. Statistical analyses of these data (see STAR Methods) generated numerical measures of the morphological disparities of the pterosaur manus and pes that were then framed within a broader context using a comparative dataset for a wide range of amniotes, including reptiles, birds, and mammals (supplemental information). Among these extant groups, phalangeal proportions—most notably the relative proportions of the phalanges of manual and pedal digit III—are strongly correlated with locomotor ecology (see STAR Methods). By comparing this dataset with the same phalangeal proportions for the manus and pes of pterosaurs, we were able to infer their likely non-aerial locomotor ecologies. Finally, we integrated these results with a phylogenetic analysis enabling us to use ancestral reconstruction to position these pterosaur locomotor ecologies within a broader macroevolutionary context. The results of this analysis revealed a macroevolutionary event in which pterodactyloid pterosaurs invaded terrestrial environments in the Middle Jurassic. This transition marked the emergence of proficient terrestrial ability in pterosaurs, triggering a dramatic diversification of dietary ecologies. Additionally, they achieved an extraordinary range of body sizes, unmatched by any other flying animals.2,37,38
Smyth, Robert S.H.; Breithaupt, Brent H.; Butler, Richard J.; Falkingham, Peter L.; Unwin, David M.
Hand and foot morphology maps invasion of terrestrial environments by pterosaurs in the mid-Mesozoic
Current Biology (2024) doi: 10.1016/j.cub.2024.09.014
Copyright: © 2024 The authors.
Published by Elsevier Inc. Open access.
Reprinted under a Creative Commons Attribution 4.0 International license (CC BY 4.0)
As science discovers more and more about the real history of Earth and the life on it, so the contrast between the tales in the bible and reality becomes ever starker. No wonder educated Christian apologists are now trying to present so much of the Bible as allegorical or metaphorical, and those who regard it as literally true are disappearing faster than dinosaurs after the meteor struck.
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