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Remains of an extinct diurnal Owl discovered

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  • Remains of an extinct diurnal Owl discovered

    Researchers have discovered the spectacularly preserved remains of an owl in the Linxia Basin in Gansu province, up in the high-elevation Liushu Formation close to the northeastern edge of the Tibetan Plateau, that lived between 6 to 10 mya (Late Miocene), which unlike most other owls, was diurnal (which is to say, active chiefly during daylight hours). In fact, this specimen preserves the oldest evidence for daytime behavior in owls.

    The bird measured at about 30cm (12") from rostrum to pubis, and a likely body mass of between 236 and 318 gms (0.520–0.701 lb.). The remains themselves preserved nearly the entire skeleton from its head to feet, including the tail bone. Basically, this nearly complete articulated bird skeleton lacks only the right forelimb and left manual digits.

    The team named the owl Miosuria diurna with the first or genus name being in reference to the Miocene age of the specimen combined with the extant genus of owl, Surnia, with which it shares many morphological features. The second or species name refers to the evidence that this owl was an active diurnal bird.

    The researchers said that they examined Miosuria's eye bones and then compared their characteristics with those of some 360 species of bird and 55 species of reptile, leading them to conclude that the owl was diunal. Further analysis of the remains revealed that Miosuria had descended from fully nocturnal owls.

    Li Zhiheng, the lead author of the study and a researcher with the Chinese Academy of Sciences' Institute of Vertebrate Paleontology and Paleoanthropology, said the discovery represents the first trace of an ancient daytime-active owl and that the evolution of diurnal owls might be linked to changes in the climate and environment in the Tibetan Plateau, but more research is needed to confirm this.


    Source: Meet the ancient owl that embraced daylight


    Millions of years ago, one owl species moved off the night shift, shaping a lifestyle for some modern birds of prey.

    Not every owl is a night owl. Of the 200-plus owl species that fly the world today, the vast majority are nocturnal or crepuscular and hunt at dusk, night, or dawn. But a select few are diurnal or cathemeral, meaning they’re most active in the daytime, or really, anytime.

    This can be determined by a species’ habitat, as well as their diet. For example, snowy owls spend their summers in the Arctic, when the sun stays up for 12 to 24 hours a day. They also mainly eat lemmings, chunky rodents that are easier to catch on the tundra while it’s light out.

    But what would cause these finely tuned hunters to switch their schedules? A study published today in the journal PNAStraces an “evolutionary reversal” in one of the largest living groups of owls and presents “the first fossil evidence for diurnal behavior” among the birds, according to the abstract.

    The research focuses on a well-preserved skeleton from northern China’s Ma Liushu Formation. Measuring about 12 inches from head to toe, Miosurnia diurna is estimated to be 6 to 10 million years old and is related to modern diurnal species such as burrowing owls and Northern hawk owls.

    Paleontologists from the Chinese Academy of Sciences analyzed the size and shape of the extinct bird’s eye, cranial, and lower leg bones and compared them to measurements from modern relatives. The authors found that the morphological features of the fossil jibed closely with day-hunting species from the group Surniini, which includes several North American owls, including the short-eared owl and ferruginous pygmy-owl.


    They also dissected an undigested food pellet in the specimen’s stomach and discovered small mammal bones like the ones extracted from kestrels (a miniature falcon that hunts by day) from the same time period. The two birds might have coexisted in dry, high savannah along the Tibetan Plateau, but “likely used different foraging strategies,” the researchers write in the paper.

    In contrast with other ancient owls, whose senses of sight, sound, and even smell were suited to the darkness, Miosurnia diurna seemed to be better adapted for daytime, with large eyes and less-tubular ears that match the traits in grassland owls today. As such, the extinct owl’s environment might have been the main driver behind its behavioral shift: The study goes so far to attribute the night-to-day switch to “steppe habitat expansion and climate cooling in the late Miocene.”

    For Jonathan Slaght, a biologist with the Wildlife Conservation Society, the details of Miosurnia diurna’s surroundings are almost as interesting as its evolutionary history. “It’s neat that the research shows that there were probably owls in savannahs,” he says (the paleontological record on grassland birds is still relatively patchy). But he also sees similarities between the ancient species and the bird he studies in Siberia, the Blakiston’s fish-owl. Both are part of the diverse Strigidae family, and are outliers in a way. “I feel some kinship,” Slaght says. “By modern standards this is a weird owl, and Blakiston’s fall into that category.” Though fish-owls are crepuscular, they lack key nocturnal features like wide facial discs and silent flight. This might be because they hunt in rivers, not woods, and have a different set of strategies for hooking prey.

    Miosurnia diurna’s bones tease its specialized hunting skills—but its DNA could reveal far more. In their paper, the paleontologists mention that the genetic underpinnings of diurnal adaptations “would be a fruitful area of research” for others to explore. But it all points to a much larger question: What made owls become owls? Slaght, for one, isn’t making any assumptions: “I like to see owls being unexpected,” he says. Maybe, that’s what defines them in part, too.



    Source

    © Copyright Original Source




    The abstract from the paper, Early evolution of diurnal habits in owls (Aves, Strigiformes) documented by a new and exquisitely preserved Miocene owl fossil from China can be read below:


    Significance

    Owls, with their largely nocturnal habits, contrast strikingly with the vast majority of diurnal birds. A new spectacular late Miocene owl skeleton from China unexpectedly preserves the oldest evidence for daytime behavior in owls. The extinct owl is a member of the clade Surniini, which contains most living diurnal owl species. Analysis of the preserved eye bones documents them as consistent with diurnal birds, and phylogenetically constrained character mapping coincides with a reconstruction of an early evolutionary reversal away from nocturnal habits in this owl group. These results support a potential Miocene origin of nonnocturnal habits in a globally distributed owl group, which may be linked to steppe habitat expansion and climatic cooling in the late Miocene.

    Abstract

    Nocturnal owls exhibit adaptations thought to be evolutionarily associated with their diets, morphologies (sensory and flight), and diel activity patterns. However, that evolutionary history is not so simple, as demonstrated by an exquisitely preserved partial skeleton of an owl from the late Miocene of China that represents the first fossil evidence for diurnal behavior among owls. The fossil from the high-elevation Liushu Formation preserves most of the skeleton including the scleral ossicles. Osteological features place the holotype specimen as a member of the strigid clade Surniini. In contrast to the largely nocturnal owls, nonnocturnal (diurnal and crepuscular) species are concentrated within the Surniini as a likely evolutionary reversal in diel activity patterns. Analyses of the preserved scleral ossicles in the fossil demonstrate that it exhibits a large exterior scleral ossicle ring diameter with a large orbital length, supporting the hypothesis that this extinct owl was largely diurnal in its habits. Furthermore, stochastic character mapping, combined with Bayesian ancestral state reconstruction of the activity patterns of extant birds, demonstrates higher posterior probabilities of diurnal behavior among early diverging Surniini, and the addition of this extinct taxon into analyses enhances the hypothesis of this clade’s diurnal origin. The fossil and associated analyses of the eye and behavioral evolution point to a long evolutionary history of nonnocturnal behavior among owls that has yet to be studied in detail. This diurnal owl joins a growing Liushu avifauna that would have hunted small mammals in the savanna-like habitats adjacent to the rising Tibetan Plateau.


    I'm always still in trouble again

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  • #2
    Interesting! Thanks for the reference.
    Glendower: I can call spirits from the vasty deep.
    Hotspur: Why, so can I, or so can any man;
    But will they come when you do call for them? Shakespeare’s Henry IV, Part 1, Act III:

    go with the flow the river knows . . .

    Frank

    I do not know, therefore everything is in pencil.

    Comment


    • #3
      Originally posted by rogue06 View Post
      Researchers have discovered the spectacularly preserved remains of an owl in the Linxia Basin in Gansu province, up in the high-elevation Liushu Formation close to the northeastern edge of the Tibetan Plateau, that lived between 6 to 10 mya (Late Miocene), which unlike most other owls, was diurnal (which is to say, active chiefly during daylight hours). In fact, this specimen preserves the oldest evidence for daytime behavior in owls.

      The bird measured at about 30cm (12") from rostrum to pubis, and a likely body mass of between 236 and 318 gms (0.520–0.701 lb.). The remains themselves preserved nearly the entire skeleton from its head to feet, including the tail bone. Basically, this nearly complete articulated bird skeleton lacks only the right forelimb and left manual digits.

      The team named the owl Miosuria diurna with the first or genus name being in reference to the Miocene age of the specimen combined with the extant genus of owl, Surnia, with which it shares many morphological features. The second or species name refers to the evidence that this owl was an active diurnal bird.

      The researchers said that they examined Miosuria's eye bones and then compared their characteristics with those of some 360 species of bird and 55 species of reptile, leading them to conclude that the owl was diunal. Further analysis of the remains revealed that Miosuria had descended from fully nocturnal owls.

      Li Zhiheng, the lead author of the study and a researcher with the Chinese Academy of Sciences' Institute of Vertebrate Paleontology and Paleoanthropology, said the discovery represents the first trace of an ancient daytime-active owl and that the evolution of diurnal owls might be linked to changes in the climate and environment in the Tibetan Plateau, but more research is needed to confirm this.


      Source: Meet the ancient owl that embraced daylight


      Millions of years ago, one owl species moved off the night shift, shaping a lifestyle for some modern birds of prey.

      Not every owl is a night owl. Of the 200-plus owl species that fly the world today, the vast majority are nocturnal or crepuscular and hunt at dusk, night, or dawn. But a select few are diurnal or cathemeral, meaning they’re most active in the daytime, or really, anytime.

      This can be determined by a species’ habitat, as well as their diet. For example, snowy owls spend their summers in the Arctic, when the sun stays up for 12 to 24 hours a day. They also mainly eat lemmings, chunky rodents that are easier to catch on the tundra while it’s light out.

      But what would cause these finely tuned hunters to switch their schedules? A study published today in the journal PNAStraces an “evolutionary reversal” in one of the largest living groups of owls and presents “the first fossil evidence for diurnal behavior” among the birds, according to the abstract.

      The research focuses on a well-preserved skeleton from northern China’s Ma Liushu Formation. Measuring about 12 inches from head to toe, Miosurnia diurna is estimated to be 6 to 10 million years old and is related to modern diurnal species such as burrowing owls and Northern hawk owls.

      Paleontologists from the Chinese Academy of Sciences analyzed the size and shape of the extinct bird’s eye, cranial, and lower leg bones and compared them to measurements from modern relatives. The authors found that the morphological features of the fossil jibed closely with day-hunting species from the group Surniini, which includes several North American owls, including the short-eared owl and ferruginous pygmy-owl.


      They also dissected an undigested food pellet in the specimen’s stomach and discovered small mammal bones like the ones extracted from kestrels (a miniature falcon that hunts by day) from the same time period. The two birds might have coexisted in dry, high savannah along the Tibetan Plateau, but “likely used different foraging strategies,” the researchers write in the paper.

      In contrast with other ancient owls, whose senses of sight, sound, and even smell were suited to the darkness, Miosurnia diurna seemed to be better adapted for daytime, with large eyes and less-tubular ears that match the traits in grassland owls today. As such, the extinct owl’s environment might have been the main driver behind its behavioral shift: The study goes so far to attribute the night-to-day switch to “steppe habitat expansion and climate cooling in the late Miocene.”

      For Jonathan Slaght, a biologist with the Wildlife Conservation Society, the details of Miosurnia diurna’s surroundings are almost as interesting as its evolutionary history. “It’s neat that the research shows that there were probably owls in savannahs,” he says (the paleontological record on grassland birds is still relatively patchy). But he also sees similarities between the ancient species and the bird he studies in Siberia, the Blakiston’s fish-owl. Both are part of the diverse Strigidae family, and are outliers in a way. “I feel some kinship,” Slaght says. “By modern standards this is a weird owl, and Blakiston’s fall into that category.” Though fish-owls are crepuscular, they lack key nocturnal features like wide facial discs and silent flight. This might be because they hunt in rivers, not woods, and have a different set of strategies for hooking prey.

      Miosurnia diurna’s bones tease its specialized hunting skills—but its DNA could reveal far more. In their paper, the paleontologists mention that the genetic underpinnings of diurnal adaptations “would be a fruitful area of research” for others to explore. But it all points to a much larger question: What made owls become owls? Slaght, for one, isn’t making any assumptions: “I like to see owls being unexpected,” he says. Maybe, that’s what defines them in part, too.



      Source

      © Copyright Original Source




      The abstract from the paper, Early evolution of diurnal habits in owls (Aves, Strigiformes) documented by a new and exquisitely preserved Miocene owl fossil from China can be read below:


      Significance

      Owls, with their largely nocturnal habits, contrast strikingly with the vast majority of diurnal birds. A new spectacular late Miocene owl skeleton from China unexpectedly preserves the oldest evidence for daytime behavior in owls. The extinct owl is a member of the clade Surniini, which contains most living diurnal owl species. Analysis of the preserved eye bones documents them as consistent with diurnal birds, and phylogenetically constrained character mapping coincides with a reconstruction of an early evolutionary reversal away from nocturnal habits in this owl group. These results support a potential Miocene origin of nonnocturnal habits in a globally distributed owl group, which may be linked to steppe habitat expansion and climatic cooling in the late Miocene.

      Abstract

      Nocturnal owls exhibit adaptations thought to be evolutionarily associated with their diets, morphologies (sensory and flight), and diel activity patterns. However, that evolutionary history is not so simple, as demonstrated by an exquisitely preserved partial skeleton of an owl from the late Miocene of China that represents the first fossil evidence for diurnal behavior among owls. The fossil from the high-elevation Liushu Formation preserves most of the skeleton including the scleral ossicles. Osteological features place the holotype specimen as a member of the strigid clade Surniini. In contrast to the largely nocturnal owls, nonnocturnal (diurnal and crepuscular) species are concentrated within the Surniini as a likely evolutionary reversal in diel activity patterns. Analyses of the preserved scleral ossicles in the fossil demonstrate that it exhibits a large exterior scleral ossicle ring diameter with a large orbital length, supporting the hypothesis that this extinct owl was largely diurnal in its habits. Furthermore, stochastic character mapping, combined with Bayesian ancestral state reconstruction of the activity patterns of extant birds, demonstrates higher posterior probabilities of diurnal behavior among early diverging Surniini, and the addition of this extinct taxon into analyses enhances the hypothesis of this clade’s diurnal origin. The fossil and associated analyses of the eye and behavioral evolution point to a long evolutionary history of nonnocturnal behavior among owls that has yet to be studied in detail. This diurnal owl joins a growing Liushu avifauna that would have hunted small mammals in the savanna-like habitats adjacent to the rising Tibetan Plateau.
      Just noticed that I kept referring to it as Miosuria diurna when it is in fact Miosurnia diurna.

      As I noted previously this fossil is amazingly complete, including some parts that rarely if ever fossilize, such as the trachea and the horseshoe-shaped hyoid (bone that the larynx and tongue attach to), as well as its patella (kneecap) along with some of the tendons used for wing and leg muscles. And along with that the remnants of the specimen's last meal, a small mammal of some sort, were also found within its gut.



      This images shows the scleral ossicles (in pale green), the overlapping ring of small bones embedded in the eye of birds, reptiles and other non-mammalian vertebrates, that allowed the researchers to determine that Miosurnia was in fact diurnal.


      I'm always still in trouble again

      "You're by far the worst poster on TWeb" and "TWeb's biggest liar" --starlight (the guy who says Stalin was a right-winger)
      "Overall I would rate the withdrawal from Afghanistan as by far the best thing Biden's done" --Starlight
      "Of course, human life begins at fertilization that’s not the argument." --Tassman

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