• Ground sloth was an opportunistic omnivore

    From Pandora@21:1/5 to All on Fri Oct 8 20:29:48 2021
    Isotope data from amino acids indicate Darwin’s ground sloth was not
    an herbivore.

    Abstract

    Fossil sloths are regarded as obligate herbivores for reasons
    including peculiarities of their craniodental morphology and that all
    living sloths feed exclusively on plants. We challenge this view based
    on isotopic analyses of nitrogen of specific amino acids, which show
    that Darwin’s ground sloth Mylodon darwinii was an opportunistic
    omnivore. This direct evidence of omnivory in an ancient sloth
    requires reevaluation of the ecological structure of South American
    Cenozoic mammalian communities, as sloths represented a major
    component of these ecosystems across the past 34 Myr. Furthermore, by
    analyzing modern mammals with known diets, we provide a basis for
    reliable interpretation of nitrogen isotopes of amino acids of
    fossils. We argue that a widely used equation to determine trophic
    position is unnecessary, and that the relative isotopic values of the
    amino acids glutamate and phenylalanine alone permit reliable
    reconstructions of trophic positions of extant and extinct mammals.

    Open access:
    https://www.nature.com/articles/s41598-021-97996-9

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Daud Deden@21:1/5 to Pandora on Fri Oct 8 20:06:04 2021
    On Friday, October 8, 2021 at 2:29:50 PM UTC-4, Pandora wrote:
    Isotope data from amino acids indicate Darwin’s ground sloth was not
    an herbivore.

    Abstract

    Fossil sloths are regarded as obligate herbivores for reasons
    including peculiarities of their craniodental morphology and that all
    living sloths feed exclusively on plants. We challenge this view based
    on isotopic analyses of nitrogen of specific amino acids, which show
    that Darwin’s ground sloth Mylodon darwinii was an opportunistic
    omnivore. This direct evidence of omnivory in an ancient sloth
    requires reevaluation of the ecological structure of South American
    Cenozoic mammalian communities, as sloths represented a major
    component of these ecosystems across the past 34 Myr. Furthermore, by analyzing modern mammals with known diets, we provide a basis for
    reliable interpretation of nitrogen isotopes of amino acids of
    fossils. We argue that a widely used equation to determine trophic
    position is unnecessary, and that the relative isotopic values of the
    amino acids glutamate and phenylalanine alone permit reliable reconstructions of trophic positions of extant and extinct mammals.

    Open access:
    https://www.nature.com/articles/s41598-021-97996-9
    Very cool. So maybe marine sloths ate algae and animals.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From erik simpson@21:1/5 to daud....@gmail.com on Fri Oct 8 20:34:56 2021
    On Friday, October 8, 2021 at 8:06:05 PM UTC-7, daud....@gmail.com wrote:
    On Friday, October 8, 2021 at 2:29:50 PM UTC-4, Pandora wrote:
    Isotope data from amino acids indicate Darwin’s ground sloth was not
    an herbivore.

    Abstract

    Fossil sloths are regarded as obligate herbivores for reasons
    including peculiarities of their craniodental morphology and that all living sloths feed exclusively on plants. We challenge this view based
    on isotopic analyses of nitrogen of specific amino acids, which show
    that Darwin’s ground sloth Mylodon darwinii was an opportunistic omnivore. This direct evidence of omnivory in an ancient sloth
    requires reevaluation of the ecological structure of South American Cenozoic mammalian communities, as sloths represented a major
    component of these ecosystems across the past 34 Myr. Furthermore, by analyzing modern mammals with known diets, we provide a basis for
    reliable interpretation of nitrogen isotopes of amino acids of
    fossils. We argue that a widely used equation to determine trophic position is unnecessary, and that the relative isotopic values of the amino acids glutamate and phenylalanine alone permit reliable reconstructions of trophic positions of extant and extinct mammals.

    Open access:
    https://www.nature.com/articles/s41598-021-97996-9
    Very cool. So maybe marine sloths ate algae and animals.

    Marine sloths? I didn't know there was such a thing. I am enlightened.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Daud Deden@21:1/5 to erik simpson on Fri Oct 8 21:00:30 2021
    On Friday, October 8, 2021 at 11:34:57 PM UTC-4, erik simpson wrote:
    On Friday, October 8, 2021 at 8:06:05 PM UTC-7, daud....@gmail.com wrote:
    On Friday, October 8, 2021 at 2:29:50 PM UTC-4, Pandora wrote:
    Isotope data from amino acids indicate Darwin’s ground sloth was not an herbivore.

    Abstract

    Fossil sloths are regarded as obligate herbivores for reasons
    including peculiarities of their craniodental morphology and that all living sloths feed exclusively on plants. We challenge this view based on isotopic analyses of nitrogen of specific amino acids, which show that Darwin’s ground sloth Mylodon darwinii was an opportunistic omnivore. This direct evidence of omnivory in an ancient sloth
    requires reevaluation of the ecological structure of South American Cenozoic mammalian communities, as sloths represented a major
    component of these ecosystems across the past 34 Myr. Furthermore, by analyzing modern mammals with known diets, we provide a basis for reliable interpretation of nitrogen isotopes of amino acids of
    fossils. We argue that a widely used equation to determine trophic position is unnecessary, and that the relative isotopic values of the amino acids glutamate and phenylalanine alone permit reliable reconstructions of trophic positions of extant and extinct mammals.

    Open access:
    https://www.nature.com/articles/s41598-021-97996-9
    Very cool. So maybe marine sloths ate algae and animals.
    Marine sloths? I didn't know there was such a thing. I am enlightened.

    Great. Now see my bizarre comment about kansaignathus sogdiana and please enlighten me. Its important.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From John Harshman@21:1/5 to erik simpson on Fri Oct 8 21:05:46 2021
    On 10/8/21 8:34 PM, erik simpson wrote:
    On Friday, October 8, 2021 at 8:06:05 PM UTC-7, daud....@gmail.com wrote:
    On Friday, October 8, 2021 at 2:29:50 PM UTC-4, Pandora wrote:
    Isotope data from amino acids indicate Darwin’s ground sloth was not
    an herbivore.

    Abstract

    Fossil sloths are regarded as obligate herbivores for reasons
    including peculiarities of their craniodental morphology and that all
    living sloths feed exclusively on plants. We challenge this view based
    on isotopic analyses of nitrogen of specific amino acids, which show
    that Darwin’s ground sloth Mylodon darwinii was an opportunistic
    omnivore. This direct evidence of omnivory in an ancient sloth
    requires reevaluation of the ecological structure of South American
    Cenozoic mammalian communities, as sloths represented a major
    component of these ecosystems across the past 34 Myr. Furthermore, by
    analyzing modern mammals with known diets, we provide a basis for
    reliable interpretation of nitrogen isotopes of amino acids of
    fossils. We argue that a widely used equation to determine trophic
    position is unnecessary, and that the relative isotopic values of the
    amino acids glutamate and phenylalanine alone permit reliable
    reconstructions of trophic positions of extant and extinct mammals.

    Open access:
    https://www.nature.com/articles/s41598-021-97996-9
    Very cool. So maybe marine sloths ate algae and animals.

    Marine sloths? I didn't know there was such a thing. I am enlightened.

    Semper fi.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From erik simpson@21:1/5 to John Harshman on Fri Oct 8 21:39:50 2021
    On Friday, October 8, 2021 at 9:05:51 PM UTC-7, John Harshman wrote:
    On 10/8/21 8:34 PM, erik simpson wrote:
    On Friday, October 8, 2021 at 8:06:05 PM UTC-7, daud....@gmail.com wrote:
    On Friday, October 8, 2021 at 2:29:50 PM UTC-4, Pandora wrote:
    Isotope data from amino acids indicate Darwin’s ground sloth was not >>> an herbivore.

    Abstract

    Fossil sloths are regarded as obligate herbivores for reasons
    including peculiarities of their craniodental morphology and that all >>> living sloths feed exclusively on plants. We challenge this view based >>> on isotopic analyses of nitrogen of specific amino acids, which show
    that Darwin’s ground sloth Mylodon darwinii was an opportunistic
    omnivore. This direct evidence of omnivory in an ancient sloth
    requires reevaluation of the ecological structure of South American
    Cenozoic mammalian communities, as sloths represented a major
    component of these ecosystems across the past 34 Myr. Furthermore, by >>> analyzing modern mammals with known diets, we provide a basis for
    reliable interpretation of nitrogen isotopes of amino acids of
    fossils. We argue that a widely used equation to determine trophic
    position is unnecessary, and that the relative isotopic values of the >>> amino acids glutamate and phenylalanine alone permit reliable
    reconstructions of trophic positions of extant and extinct mammals.

    Open access:
    https://www.nature.com/articles/s41598-021-97996-9
    Very cool. So maybe marine sloths ate algae and animals.

    Marine sloths? I didn't know there was such a thing. I am enlightened.

    Semper fi.
    Oorah!

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Pandora@21:1/5 to eastside.erik@gmail.com on Sat Oct 9 12:26:28 2021
    On Fri, 8 Oct 2021 20:34:56 -0700 (PDT), erik simpson
    <eastside.erik@gmail.com> wrote:

    On Friday, October 8, 2021 at 8:06:05 PM UTC-7, daud....@gmail.com wrote:
    On Friday, October 8, 2021 at 2:29:50 PM UTC-4, Pandora wrote:
    Isotope data from amino acids indicate Darwin’s ground sloth was not
    an herbivore.

    Abstract

    Fossil sloths are regarded as obligate herbivores for reasons
    including peculiarities of their craniodental morphology and that all
    living sloths feed exclusively on plants. We challenge this view based
    on isotopic analyses of nitrogen of specific amino acids, which show
    that Darwin’s ground sloth Mylodon darwinii was an opportunistic
    omnivore. This direct evidence of omnivory in an ancient sloth
    requires reevaluation of the ecological structure of South American
    Cenozoic mammalian communities, as sloths represented a major
    component of these ecosystems across the past 34 Myr. Furthermore, by
    analyzing modern mammals with known diets, we provide a basis for
    reliable interpretation of nitrogen isotopes of amino acids of
    fossils. We argue that a widely used equation to determine trophic
    position is unnecessary, and that the relative isotopic values of the
    amino acids glutamate and phenylalanine alone permit reliable
    reconstructions of trophic positions of extant and extinct mammals.

    Open access:
    https://www.nature.com/articles/s41598-021-97996-9
    Very cool. So maybe marine sloths ate algae and animals.

    Marine sloths? I didn't know there was such a thing. I am enlightened.

    There used to be in the Miocene and Pliocene:

    https://en.wikipedia.org/wiki/Thalassocnus

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Daud Deden@21:1/5 to Pandora on Sat Oct 9 09:00:41 2021
    On Saturday, October 9, 2021 at 6:26:31 AM UTC-4, Pandora wrote:
    On Fri, 8 Oct 2021 20:34:56 -0700 (PDT), erik simpson
    <eastsi...@gmail.com> wrote:

    On Friday, October 8, 2021 at 8:06:05 PM UTC-7, daud....@gmail.com wrote: >> On Friday, October 8, 2021 at 2:29:50 PM UTC-4, Pandora wrote:
    Isotope data from amino acids indicate Darwin’s ground sloth was not >> > an herbivore.

    Abstract

    Fossil sloths are regarded as obligate herbivores for reasons
    including peculiarities of their craniodental morphology and that all >> > living sloths feed exclusively on plants. We challenge this view based >> > on isotopic analyses of nitrogen of specific amino acids, which show
    that Darwin’s ground sloth Mylodon darwinii was an opportunistic
    omnivore. This direct evidence of omnivory in an ancient sloth
    requires reevaluation of the ecological structure of South American
    Cenozoic mammalian communities, as sloths represented a major
    component of these ecosystems across the past 34 Myr. Furthermore, by >> > analyzing modern mammals with known diets, we provide a basis for
    reliable interpretation of nitrogen isotopes of amino acids of
    fossils. We argue that a widely used equation to determine trophic
    position is unnecessary, and that the relative isotopic values of the >> > amino acids glutamate and phenylalanine alone permit reliable
    reconstructions of trophic positions of extant and extinct mammals.

    Open access:
    https://www.nature.com/articles/s41598-021-97996-9
    Very cool. So maybe marine sloths ate algae and animals.

    Marine sloths? I didn't know there was such a thing. I am enlightened.
    There used to be in the Miocene and Pliocene:

    https://en.wikipedia.org/wiki/Thalassocnus

    Swim faster than walking quadrupedally or climbing
    https://www.youtube.com/watch?v=Z22yFkyfYaE

    Good video on sloth diversification
    https://www.youtube.com/watch?v=pt9tBtQoAHo

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)