New information on the Hind limb feathering, soft tissues and skeleton of Microraptor (Theropoda: Dromaeosauridae)

BMC Ecology and Evolution, Journal Year: 2025, Volume and Issue: 25(1)

Published: April 24, 2025

Abstract Background Microraptor is known as the most significant example of extended feathering on legs a paravian, both fossil and modern. Its striking difference with paravians contributes to multiple theories function its conspicuous hind limbs. Recent studies tried uncover evolutionary significance, but anatomy has only been described from small number samples. Results Through analysis 16 specimens , including 8 previously undescribed specimens, here we provide new information structure hindwing feathers within revised feather taxonomy, shape which displays all along limb, except pedal digits. Here describe in detail 6 types: metatarsal remiges, long coverts, femoral well first description tibial feathers, anterior coverts minor coverts. Our study BMNHC PH881 STM 5–5, 5–75, 6–62 6–86 partially consistent previous work, key this proximal shift triangular wing portion formed by that outlines joint between tibiotarsus metatarsus. This configuration does not exist any extant or bird, other non-avian paravian so far, underscoring uniqueness . Unlike reconstructions, display an asymmetrical close-vanned remiges. The preserved are posteriorly projected metatarsus vary medioposterior lateroposterior projection feathers. Conclusions overall layers found two elongated asymmetrically vaned linked more reminiscent forewing modern birds than leg fossils taxa. These observations allow us better understand flight, non-flight locomotion hunting strategies iconic ‘four-winged’ dinosaur suggesting had complex behaviour made it adapted arboreal terrestrial habitats.

Language: Английский

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Reconstructing the dietary habits and trophic positions of the Longipterygidae (Aves: Enantiornithes) using neontological and comparative morphological methods

PeerJ, Journal Year: 2023, Volume and Issue: 11, P. e15139 - e15139

Published: March 27, 2023

The Longipterygidae are a unique clade among the enantiornithines in that they exhibit elongate rostra (≥60% total skull length) with dentition restricted to distal tip of rostrum, and pedal morphologies suited for an arboreal lifestyle (as other enantiornithines). This suite features has made interpretations this group’s diet ecology difficult determine due lack analogous taxa similar together. Many extant bird groups rostral elongation, which is associated several disparate ecologies diets ( e.g ., aerial insectivory, piscivory, terrestrial carnivory). Thus, presence elongation only somewhat refines trophic predictions clade. Anatomical do not function singularly but as part whole thus, any dietary or ecological hypothesis regarding must also consider such their dentition. group dentulous volant tetrapods chiropterans, tooth morphology enamel thickness vary depending upon food preference. Drawing inferences from both avian bill proportions variations dental extinct taxa, we provide quantitative data support were animalivorous, greater insectivory.

Language: Английский

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Morphological disparity and structural performance of the dromaeosaurid skull informs ecology and evolutionary history

BMC Ecology and Evolution, Journal Year: 2024, Volume and Issue: 24(1)

Published: April 16, 2024

Abstract Non-avialan theropod dinosaurs had diverse ecologies and varied skull morphologies. Previous studies of cranial morphology mostly focused on higher-level taxa or characteristics associated with herbivory. To better understand morphological disparity function within carnivorous families, here we focus the Dromaeosauridae, ‘raptors’ traditionally seen as agile hunters. We applied 2D geometric morphometrics to quantify shape, performed mechanical advantage analysis assess efficiency bite force transfer, finite element examine strain distribution in during biting. find that dromaeosaurid was less disparate than most non-avialan groups. Their skulls show a continuum form between those are tall short flat long. hypothesise this narrower indicates developmental constraint observed some mammalian families. Mechanical Dromaeosaurus albertensis Deinonychus antirrhopus were adapted for relatively high forces, while Halszkaraptor escuilliei speed, other dromaeosaurids intermediate forces speeds. Finite regions consistent families but differ them. Average levels do not follow any phylogenetic pattern, possibly due ecological convergence distantly-related taxa. Combining our new morphofunctional data re-evaluation previous evidence, piscivorous reconstructions be unlikely, instead suggest an invertivorous diet possible adaptations feeding murky water low-visibility conditions. support being taking large vertebrate prey, its is resistant dromaeosaurids. Given recovery resistance Velociraptor mongoliensis , which believed have regularly engaged scavenging behaviour, higher taxon may reflect greater reliance rather fresh kills. Comparisons troodontid Gobivenator gracile rostrum like ancestral their closest common ancestor (Deinonychosauria) robust rostra derived condition. also displays jaw lower examined dromaeosaurids, given hypothesised divergence troodontids from it unclear group, if either, represents Future work extending sampling would therefore invaluable provide much needed context origin early birds. This study illustrates how shape functional metrics can discern ecology at taxonomic identify variants feeding.

Language: Английский

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An extraordinary fossil captures the struggle for existence during the Mesozoic

Scientific Reports, Journal Year: 2023, Volume and Issue: 13(1)

Published: July 18, 2023

Abstract Dinosaurs and mammals have coexisted for the last ~ 230 million years. Both groups arose during Late Triassic diversified throughout Mesozoic into Cenozoic (the latter in form of birds). Although they undoubtedly interacted many ways, direct fossil evidence their interaction is rare. Here we report a new find from Lujiatun Member Lower Cretaceous Yixian Formation China, showing gobiconodontid mammal psittacosaurid dinosaur locked mortal combat. We entertain various hypothesized explanations this association, but balance suggests that it represents predation attempt on part smaller mammal, suddenly interrupted by, preserved within, lahar-type volcanic debris flow. are usually depicted as having lived shadows larger dinosaurian contemporaries, convincingly demonstrates could pose threat even to near fully-grown dinosaurs. The Formation—and Chinese Jehol Biota more broadly—have played particularly important role revealing diversity small-bodied dinosaurs other fauna. anticipate volcanically derived obrution deposits specific will likewise continue yield biotic interactions otherwise unknown rest record.

Language: Английский

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New biogeochemical insights into Mesozoic terrestrial paleoecology and evidence for omnivory in troodontid dinosaurs

Geological Society of America Bulletin, Journal Year: 2023, Volume and Issue: 136(7-8), P. 2689 - 2701

Published: Nov. 15, 2023

Abstract The Cretaceous paleocommunities of North America preserve a rich record biodiversity that suggests many species occupied narrow biogeographic ranges in comparison to their ecological equivalents extant systems. How taxa these systems partitioned niches and structured communities can be difficult determine from fossils alone, which has led variety hypotheses concerning diets habitat use. Here, we examine element ratios (Sr/Ca, Ba/Ca) the enamel suite co-occurring vertebrate sampled spatiotemporally constrained interval Oldman Formation Alberta, Canada, reconstruct trophic structure, use δ13C, δ18O, 87Sr/86Sr compositions test for niche partitioning among hadrosaurids, ceratopsids, ankylosaurs. We also previously proposed dietary troodontid theropods. In large ornithischians, find Ba/Ca Sr/Ca are consistent with herbivory, hadrosaurs distinct ceratopsids ankylosaurids ranges, pattern is indicative differences use/breadth, plant sources, feeding height. mammals, varanoid lizards, dromaeosaurids, tyrannosaurids gradient lower animal-dominant omnivorous faunivorous diets. Troodontids, have been variably hypothesized as either faunivorous, omnivorous, or herbivorous due unusual dentition, fall between those ornithischians dromaeosaurids. From multi-proxy data, interpret troodontids mixed-feeding plant-dominant omnivores. These proxies represent valuable tool understanding community ecology ecosystems hold enormous potential future research paleobiology.

Language: Английский

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Cannibalism in the Early Jurassic bony fish Pachycormus macropterus (Teleosteomorpha: Pachycormiformes) and its paleoecological significanceCitation for this article: Cooper, S. L. A. (2024) Cannibalism in the Early Jurassic bony fish Pachycormus macropterus (Teleosteomorpha: Pachycormiformes) and its paleoecological significance. Journal of Vertebrate Paleontology . https://doi.org/10.1080/02724634.2023.2294000

Journal of Vertebrate Paleontology, Journal Year: 2023, Volume and Issue: 43(3)

Published: May 4, 2023

Cannibalism (conspecific predation) is a surprisingly common and widespread behavior in modern ecosystems; however, direct evidence for cannibalism strongly lacking the fossil record. Identifying important to help better understand recondite trophic interactions between extinct species, as well detect potential resource pressures competition their ecosystems. Here, I describe first cannibalistic diet pachycormiform fish, based on three exceptionally well-preserved specimens of Pachycormus macropterus (de Blainville, 1818) with conspecific gut contents from Early Jurassic (Toarcian) Normandy (France). The generalist proven be more complex than previously considered, which has recently been shown include vampyropod squids, belemnoteuthids, ammonites, small teleosts. All prey fishes were ingested whole longitudinal orientation, revealing that actively hunted juveniles its own kind was an indiscriminate opportunistic predator. cannibal individuals themselves are also juveniles, further supporting previous findings dietary shift piscivorous teuthophagous over ontogeny. Despite European distribution Pachycormus, only area show cannibalism, suggesting conventional resources either scarce or restricted at site, prompting indiscriminately predate one another.

Language: Английский

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Peer Review #2 of "Reconstructing the dietary habits and trophic positions of the Longipterygidae (Aves: Enantiornithes) using neontological and comparative morphological methods (v0.3)"

Published: March 27, 2023

The Longipterygidae are a unique clade among the enantiornithines in that they exhibit elongate rostra ( 60% total skull length) with dentition restricted to distal tip of rostrum, and pedal morphologies suited for an arboreal lifestyle (as other enantiornithines).This suite features has made interpretations this group's diet ecology difficult determine due lack analogous taxa similar together.Many extant bird groups rostral elongation, which is associated several disparate ecologies diets (e.g., aerial insectivory, piscivory, terrestrial carnivory).Thus, presence elongation only somewhat refines trophic predictions clade.Anatomical do not function singularly but as part whole thus, any dietary or ecological hypothesis regarding must also consider such their dentition.The group dentulous volant tetrapods chiropterans, tooth morphology enamel thickness vary depending upon food preference.Drawing inferences from both avian bill proportions variations dental extinct taxa, we provide quantitative data support were animalivorous, greater insectivory.

Language: Английский

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Peer Review #2 of "Reconstructing the dietary habits and trophic positions of the Longipterygidae (Aves: Enantiornithes) using neontological and comparative morphological methods (v0.2)"

Published: March 27, 2023

The Longipterygidae are a unique clade among the enantiornithines in that they exhibit elongate rostra ( 60% total skull length) with dentition restricted to distal tip of rostrum, and pedal morphologies suited for an arboreal lifestyle (as other enantiornithines).This suite features has made interpretations this group's diet ecology difficult determine due lack analogous taxa similar together.Many extant bird groups rostral elongation, which is associated several disparate ecologies diets (e.g., aerial insectivory, piscivory, terrestrial carnivory).Thus, presence elongation only somewhat refines trophic predictions clade.Anatomical do not function singularly but as part whole thus, any dietary or ecological hypothesis regarding must also consider such their dentition.The group dentulous volant tetrapods chiropterans, tooth morphology enamel thickness vary depending upon food preference.Drawing inferences from both avian bill proportions variations dental extinct taxa, we provide quantitative data support were animalivorous, greater insectivory.

Language: Английский

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Peer Review #1 of "Reconstructing the dietary habits and trophic positions of the Longipterygidae (Aves: Enantiornithes) using neontological and comparative morphological methods (v0.1)"

Published: March 27, 2023

The Longipterygidae are a unique clade among the enantiornithines in that they exhibit elongate rostra ( 60% total skull length) with dentition restricted to distal tip of rostrum, and pedal morphologies suited for an arboreal lifestyle (as other enantiornithines).This suite features has made interpretations this group's diet ecology difficult determine due lack analogous taxa similar together.Many extant bird groups rostral elongation, which is associated several disparate ecologies diets (e.g., aerial insectivory, piscivory, terrestrial carnivory).Thus, presence elongation only somewhat refines trophic predictions clade.Anatomical do not function singularly but as part whole thus, any dietary or ecological hypothesis regarding must also consider such their dentition.The group dentulous volant tetrapods chiropterans, tooth morphology enamel thickness vary depending upon food preference.Drawing inferences from both avian bill proportions variations dental extinct taxa, we provide quantitative data support were animalivorous, greater insectivory.

Language: Английский

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Peer Review #2 of "Reconstructing the dietary habits and trophic positions of the Longipterygidae (Aves: Enantiornithes) using neontological and comparative morphological methods (v0.1)"

Published: March 27, 2023

The Longipterygidae are a unique clade among the enantiornithines in that they exhibit elongate rostra ( 60% total skull length) with dentition restricted to distal tip of rostrum, and pedal morphologies suited for an arboreal lifestyle (as other enantiornithines).This suite features has made interpretations this group's diet ecology difficult determine due lack analogous taxa similar together.Many extant bird groups rostral elongation, which is associated several disparate ecologies diets (e.g., aerial insectivory, piscivory, terrestrial carnivory).Thus, presence elongation only somewhat refines trophic predictions clade.Anatomical do not function singularly but as part whole thus, any dietary or ecological hypothesis regarding must also consider such their dentition.The group dentulous volant tetrapods chiropterans, tooth morphology enamel thickness vary depending upon food preference.Drawing inferences from both avian bill proportions variations dental extinct taxa, we provide quantitative data support were animalivorous, greater insectivory.

Language: Английский

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