Tsis tshua muaj pob txha ntawm cov dev qub pom los ntawm paleontologists

Cov canines no ntseeg tau tias tau taug kev hauv cheeb tsam San Diego mus txog 28 lab xyoo dhau los.

Kev sib raug zoo ntawm tib neeg thiab dev rov qab mus ntau txhiab xyoo. Thaum tib neeg thawj tsiv teb tsaws chaw rau North America, lawv coj lawv cov dev nrog lawv. Cov dev no tau siv los tua tsiaj thiab muab kev sib raug zoo rau lawv cov tswv. Tab sis ntev ua ntej cov canines tuaj txog ntawm no, muaj predatory doglike canid hom uas tua cov nyom thiab hav zoov ntawm Americas.

Tsis tshua muaj pob txha ntawm cov dev qub pom los ntawm paleontologists 1
Cov pob txha taub hau ib nrab (ntsig rau sab xis) ntawm Archeocyon, ib hom dev zoo li qub uas nyob hauv thaj chaw uas tam sim no San Diego txog 28 lab xyoo dhau los. © San Diego Natural History Tsev khaws puav pheej / Kev Siv Ncaj Ncees

Ib qho tsis tshua muaj thiab yuav luag tiav cov pob txha pob txha ntawm ib qho ntawm cov tsiaj uas ploj mus ntev tau pom los ntawm Paleontologists los ntawm San Diego Natural History Museum. Nws tau pom nyob rau hauv ob lub pob zeb loj loj ntawm cov xuab zeb thiab cov av nkos tau pom hauv 2019 thaum lub sijhawm ua haujlwm hauv San Diego County Otay Ranch cov zej zog.

Cov pob txha no yog los ntawm ib pawg tsiaj hu ua Archeocyons, uas txhais tau tias "dub qub." Cov pob txha pob txha hnub mus rau lub sijhawm Oligocene lig thiab ntseeg tau tias muaj hnub nyoog 24 lab txog 28 lab xyoo.

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Amanda Linn, tus pab saib xyuas paleo ntawm San Diego Natural History Tsev khaws puav pheej, ua haujlwm ntawm lub tsev khaws puav pheej Archeocyon fossil. © San Diego Natural History Tsev khaws puav pheej / Kev Siv Ncaj Ncees

Lawv qhov kev tshawb pom tau ua rau muaj txiaj ntsig zoo rau cov kws tshawb fawb ntawm San Diego Tsev khaws puav pheej ntawm Keeb Kwm Keeb Kwm, suav nrog paleontology curator Tom Deméré, tus kws tshawb fawb tom qab kws kho mob Ashley Poust, thiab tus pab saib xyuas Amanda Linn.

Vim hais tias lub tsev khaws puav pheej cov pob txha tam sim no tsis tiav thiab muaj tsawg tsawg, Archeocyons pob txha yuav pab pawg neeg paleo sau cov khoob ntawm qhov lawv paub txog cov dev qub uas nyob hauv qhov tam sim no hu ua San Diego kaum tawm lab xyoo dhau los. .

Puas yog lawv taug kev ntawm lawv cov ntiv taw zoo li dev niaj hnub no? Puas yog lawv nyob hauv ntoo lossis burrow hauv av? Lawv noj dab tsi, thiab dab tsi creatures preyed rau lawv? Lawv txoj kev sib raug zoo li cas rau cov tsiaj zoo li dev uas ploj lawm uas tuaj ua ntej lawv? Qhov no puas yog ib hom tshiab uas tseem tsis tau pom dua? Cov pob txha pob txha no muab SDNHM cov kws tshawb fawb nrog ob peb daim ntxiv ntawm qhov tsis tiav evolutionary puzzle.

Archeocyons fossils tau pom nyob rau hauv Pacific Northwest thiab Great Plains, tab sis yuav luag tsis muaj nyob rau yav qab teb California, qhov twg glaciers thiab phaj tectonics tau tawg, tawg, thiab faus ntau fossils los ntawm lub sij hawm ntawd tob hauv av. Qhov laj thawj tseem ceeb no Archeocyons pob txha tau tshawb pom thiab xa mus rau lub tsev khaws puav pheej yog California txoj cai lij choj uas tso cai rau cov kws tshawb fawb paleontologist nyob rau hauv cov tsev loj loj los nrhiav thiab tiv thaiv cov pob txha muaj peev xwm rau kev tshawb fawb yav tom ntej.

Pat Sena, tus saib xyuas paleo rau San Diego Natural History Tsev khaws puav pheej, tau tshuaj xyuas cov pob zeb tailings hauv Otay project txog peb xyoos dhau los thaum nws pom dab tsi zoo li me me dawb pob txha tawm ntawm pob zeb excavated. Nws kos tus cim Sharpie dub rau ntawm pebbles thiab kom lawv txav mus rau hauv lub tsev cia puav pheej, qhov chaw tshawb fawb tau raug tso tseg tam sim ntawd tau ze li ob xyoos vim muaj kev sib kis.

Thaum Lub Kaum Ob Hlis 2nd 2021, Linn tau pib ua haujlwm ntawm ob lub pob zeb loj, siv cov khoom me me thiab txiav cov cuab yeej thiab txhuam kom maj mam tshem tawm cov txheej pob zeb.

Linn tau hais tias "Txhua zaus kuv pom cov pob txha tshiab, daim duab tau pom tseeb dua," Linn hais. "Kuv xav hais tias, 'Auj saib, ntawm no yog qhov chaw no sib tw nrog cov pob txha, ntawm no yog qhov chaw txha nraub qaum mus rau ob txhais ceg, ntawm no yog qhov chaw seem ntawm cov tav."

Raws li Ashley Poust ib zaug cov pob txha pob txha pob txha thiab cov hniav tau tshwm sim los ntawm pob zeb, nws tau pom tseeb tias nws yog hom kab mob qub.

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Tag nrho Archeocyon fossil ntawm San Diego Natural History Museum. © San Diego Natural History Tsev khaws puav pheej / Kev Siv Ncaj Ncees

Thaum Lub Peb Hlis 2022, Poust yog ib qho ntawm peb tus kws tshawb fawb thoob ntiaj teb uas tau tshaj tawm lawv qhov kev tshawb pom ntawm tus kab mob tshiab saber-toothed catlike predator, Diegoaelurus, los ntawm Eocene epoch.

Tab sis qhov twg cov miv thaum ub tsuas muaj nqaij-tua hniav, omnivorous canids muaj ob qho tib si txiav cov hniav nyob rau hauv pem hauv ntej los tua thiab noj cov tsiaj me thiab cov hniav zoo li cov hniav nyob rau tom qab ntawm lawv lub qhov ncauj siv los tsoo cov nroj tsuag, noob thiab berries. Qhov sib xyaw ntawm cov hniav thiab cov duab ntawm nws pob txha taub hau pab Deméré txheeb xyuas cov pob txha ua Archeocyons.

Cov pob txha pob txha yog tag nrho tsis zoo tsuas yog rau ib feem ntawm nws tus Tsov tus tw ntev. Qee qhov ntawm nws cov pob txha tau jumbled txog, tej zaum yog vim lub ntiaj teb txav tom qab tus tsiaj tuag, tab sis nws pob txha taub hau, hniav, txha nraub qaum, ceg, pob taws thiab ntiv taw ua tiav, muab cov ntaub ntawv muaj txiaj ntsig ntawm Archeocyons 'evolutionary hloov.

Qhov ntev ntawm cov pob txha pob txha pob txha uas lawv yuav tau txuas nrog Achilles tendons qhia tias Archeocyons tau yoog raws nws cov tsiaj nyeg ntev ntev hla cov nyom qhib. Nws tseem ntseeg tau tias nws lub cev muaj zog, cov leeg pob txha yuav tau siv rau kev sib npaug thaum khiav thiab ua kom ntse tig. Tseem muaj cov lus qhia los ntawm nws txhais taw tias nws muaj peev xwm tuaj yeem nyob lossis nce toj hauv ntoo.

Lub cev, Archeocyons yog qhov loj ntawm cov hma liab hnub no, nrog ob txhais ceg ntev thiab lub taub hau me me. Nws taug kev ntawm nws cov ntiv taw thiab muaj cov claws uas tsis tuaj yeem thim rov qab. Nws lub cev zoo li hma liab ntau txawv ntawm cov tsiaj uas ploj lawm paub tias yog Hesperocyons, uas me dua, ntev dua, muaj ob txhais ceg luv thiab zoo li niaj hnub weasels.

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Daim duab no ntawm San Diego Natural History Tsev khaws puav pheej los ntawm William Stout qhia tias Archeocyon canid, qhov chaw, yuav zoo li cas thaum lub sijhawm Oligocene era hauv San Diego tam sim no. © William Stout / San Diego Natural History Tsev khaws puav pheej / Kev Siv Ncaj Ncees

Thaum Archeocyons fossil tseem tab tom kawm thiab tsis yog rau pej xeem, lub tsev khaws puav pheej muaj cov khoom pov thawj tseem ceeb ntawm nws thawj pem teb nrog pob txha thiab pob txha loj loj uas sawv cev rau cov tsiaj uas nyob hauv San Diego thaj chaw ntug dej hiav txwv thaum ub.

Ashley Poust tau hais ntxiv tias ib qho ntawm cov tsiaj hauv tus kws kos duab William Stout cov duab, ib tus tsiaj zoo li hma liab sawv saum tus luav tshiab, zoo ib yam li Archeocyons yuav zoo li.