Giant Cretaceous octopuses wataƙila sun kasance top predators — amma evidence yana farawa da jaws, ba sea monsters ba

Labarin kraken, idan aka mayar da shi ga burbushin da muke da shi

Fossil jaw ba dabba gaba ɗaya ba ce. Ƙaƙƙarfan ragowar soft body ne, fragment da paleontologists dole su yi amfani da shi su reconstruct anatomy, behavior da ecology ba tare da yin kamar sun ga dabbar da rai ba. Shi ya sa wannan takarda yana da jan hankali sosai kuma yana da sauƙin oversimplify. kanun labarai mai sauƙi zai ce: giant kraken-like octopuses sun mamaye tekunan Cretaceous. Version mai hankali ya fi kyau: fossil jaws da aka adana sosai suna nuna cewa wasu daga earliest known finned octopuses manyan carnivores ne, suna crush hard prey akai-akai, kuma wataƙila sun kai saman food webs na Late Cretaceous.

Wannan ma abin mamaki ne. Amma ya kamata a karanta shi a matsayin reconstruction daga jaws, wear patterns, taxonomy da body-size scaling — ba sea-monster story ba.

Abin da marubutan suka yi

Marubutan sun sake nazarin fossil jaws daga Cretaceous octobrachian cephalopods — babban group da ya haɗa octopuses da danginsu. An riga an ruwaito manyan fossil jaws 15 daga Japan da Vancouver Island. Ƙungiyar ta kuma gano ƙarin jaws 12 a carbonate concretions guda biyar daga Japan ta digital fossil-mining.

Wannan method ya haɗa high-resolution, full-color grinding tomography da zero-shot learning AI model, wato samfurin ba a train musamman ga waɗannan fossils ba. Masu binciken sun grind kowane concretion a 50-micrometer intervals, suna ɗaukar hoto na kowace sabuwar surface don gina large sequence na color images. Segmentation model mai suna DEVA ya samar da digital outline, ko mask, na jaw a kowane image. Masu binciken sun duba outlines ɗin da original images, sannan suka stack da join su zuwa minimally smoothed, original-color 3D models. Hakan ya ba su damar gano jaws da ke ɓoye cikin rock da kuma duba fine chips, scratches da sauran wear features a surface. Grinding tomography ya lalata rock samples biyar, amma image bayanai, masks da 3D models da aka samu an archive su.

Sannan suka yi abubuwa huɗu masu haɗuwa.

Na farko, sun revised taxonomy. Fossil jaws da aka raba a species biyar a baya an sake shirya su zuwa species biyu: Nanaimoteuthis jeletzkyi da Nanaimoteuthis haggarti. Genus ɗin, wanda a baya aka ɗauka a matsayin vampire-squid relative, a nan an sanya shi cikin Cirrata, finned octopuses.

Na biyu, sun tsawaita timeline. Sabon material ya tura N. jeletzkyi zuwa earliest Cenomanian, kusan shekaru miliyan 100 da suka wuce, yana tsawaita known record na finned octopuses da kusan shekaru miliyan 15, da octopuses gaba ɗaya da kusan shekaru miliyan 5.

Na uku, sun kiyasta body size daga jaw size. Ta amfani da allometric relationships daga modern long-bodied finned octopuses, sun kiyasta mantle length sannan total length. Estimates ɗin suna da faɗin range: N. jeletzkyi kusan mita 2.8 zuwa 7.7 total length, N. haggarti kuma kusan mita 6.6 zuwa 18.6. Wannan upper range shi ne tushen “kraken” language.

Supplementary methods sun bayyana scaling chain ɗin. Masu binciken sun reconstruct worn ko weathered jaw outlines inda ya dace, sannan suka yi amfani da species-specific relationships 12 tsakanin lower-jaw hood length da mantle length. Sun account matsakaici 39% fixation shrinkage a relevant modern specimens, sannan suka canza mantle length zuwa total length da ratio 4.2 daga long-bodied living finned octopuses. Waɗannan choices suna samar da range, ba direct measurement na fossil body ba.

Na huɗu, sun duba wear. Manyan jaws sun zama blunt da rounded a wuraren da juveniles za su fi sharp jaw elements. Sun nuna chips, scratches, polished surfaces, cracks, da asymmetric loss na jaw edges. Marubutan suna interpret wannan a matsayin shaida na repeated hard-prey crushing, da possibly lateralized behavior.

Abin da suka gano

Mai yiwuwa early finned octopuses ne, ba vampire squids ba. Supplementary taxonomy ta raba linked steps biyu. Kowane bridge strip ne na jaw material da ke haɗa hood da lateral wall. A Nanaimoteuthis, waɗannan bridges inner da outer jaw plates suna ɓoye su gaba ɗaya, pattern da ke goyon bayan sanya genus a Cirrata. Broad jaw wings ɗinsa sannan suna goyon bayan sanya shi a long-bodied group na finned octopuses. Wannan yana da muhimmanci saboda takarda ba kawai yana cewa “large cephalopod” ba; yana canza inda fossils suke zaune a octopus history.

Sun yi tsufa sosai. Sabbin specimens suna sanya finned octopuses kusan shekaru miliyan 100 da suka wuce, a Cretaceous. Hakan ya sa su cikin earliest octopus-line animals da aka sani.

Za su iya kasancewa manya ƙwarai. Body-size estimates ba measurements na preserved bodies ba ne; calculations daga jaws ne. Amma numbers suna da girma ko an faɗa da hankali. Smaller species, N. jeletzkyi, an kiyasta shi da several meters total length. Larger N. haggarti an kiyasta har kusan mita 18.6, comparable in scale da manyan marine predators na lokacin da kuma manyan living cephalopods.

Jaws sun yi wear sosai. A largest specimens, lost jaw material ya kai kusan 10% na total jaw length. takarda yana cewa wannan wear ba preparation damage ko transport abrasion ba ne: specimens sun fito daga low-energy outer-shelf deposits, chips da scratches an preserve su a patterns da suka dace da amfani, kuma co-occurring fossil squid jaws ba su nuna irin pattern ɗin ba. Marubutan sun kwatanta wear da modern durophagous cephalopods — animals da ke cin hard prey.

Wear ɗin asymmetric ne. Right jaw edge ya fi left wear a species biyu. Marubutan suna interpret hakan a matsayin mai yiwuwa behavioral lateralization: preference na amfani da side guda fiye da ɗaya. Saboda lateralized behavior yana associated da complex nervous systems a modern animals, suna nuna cewa waɗannan early octopuses wataƙila sun riga sun yi advanced intelligence.

Abin da wannan mai yiwuwa yake nufi

Strongest ecological interpretation shi ne Late Cretaceous finned octopuses ba duk small background animals ba ne a ecosystems da large vertebrates suka mamaye. Top-predator case na marubutan ya haɗa gigantic estimated body size da durophagous carnivory — repeated processing na hard animal prey — inferred daga jaw wear. Tare, waɗannan findings suna goyon bayan possibility cewa invertebrate lineage ta shiga top tier na food web da ake haɗawa da mosasaurs, plesiosaurs, large fish da sharks.

Evolutionary story ma yana da ban sha’awa. Vertebrate marine predators da octopus-line cephalopods sun bi hanyoyi daban-daban zuwa predation. Vertebrates sun samu jaws, streamlined bodies, kuma galibi suka rage external armor. Octopus relatives sun rage ko internalize shells, suka zama soft-bodied da mobile, yayin da suka riƙe powerful jaws da flexible arms. takardar ta frame wannan a matsayin convergent path zuwa large, intelligent marine predators.

Part mafi speculative shi ne behavior. Extensive wear yana goyon bayan hard-prey feeding. Large size yana goyon bayan ecological importance. Asymmetric wear yana goyon bayan mai yiwuwa lateralized behavior. Amma “advanced intelligence” inference ne, ba direct fossil measurement ba. mai yiwuwa ne cikin context na octopus biology, amma bai kamata a ƙara ƙarfinsa fiye da shaida ba.

Abin da wannan ba ya tabbatar

• Ba ya preserve whole giant octopus body. Reconstruction ya dogara ne musamman da jaws, tare da body size inferred daga modern finned-octopus scaling.
• Ba ya nuna stomach contents ko direct prey remains. Hard-prey feeding inference ne daga jaw wear, ba fossilized meal ba.
• Authored research article ba ya propose cewa sun ci mosasaurs, plesiosaurs, ko other large marine reptiles. Research text ya ambace su ne kawai a matsayin comparisons na body size da ecological position.
• Ba ya ba exact body length. Estimates ranges ne, kuma largest ikirari upper estimate ne.
• Ba ya auna intelligence kai tsaye. Lateralized jaw wear an interpret shi a matsayin mai yiwuwa behavioral lateralization, wanda zai iya suggest complex behavior; wannan several inferential steps ne daga sanin abin da dabbar za ta iya yi.
• Ba ya nufin duk early octopuses giants ne. ikirarin ya shafi waɗannan Nanaimoteuthis species, musamman N. haggarti, ba kowace early octopus lineage ba.

Yaya ƙarfin shaidar yake?

Ga existence na very large Cretaceous octopus-line jaws, shaida yana da ƙarfi: takardar ta gabatar da described specimens, digital models, stratigraphic context, da comparisons da modern da fossil cephalopod jaws.

Ga hard-prey feeding, shaida ma reasonably strong ne. Wear patterns suna detailed — chips, scratches, polish, cracks, asymmetric loss — kuma marubutan sun yi ƙoƙari wajen exclude preparation damage da transport abrasion. Comparison da modern durophagous cephalopods mai yiwuwa bridge ne.

Ga exact body size da top-predator status, confidence ya kamata ya zama moderate. Size estimates sun dogara da allometric scaling daga living long-bodied finned octopuses. Ecological role inference ne daga combination na estimated size da durophagous carnivory, ba direct observation ba. Argument ɗin coherent ne, amma ecological reconstruction ne, ba direct census na food web ba.

Me ya sa yake da muhimmanci

Wannan takarda kyakkyawan misali ne na yadda paleontology ke yin strong ikirarai daga partial shaida ba tare da sihiri ba. Jaw shi ne object. Wear behavioral trace ne. Scaling curve bridge ne daga hard fossil zuwa soft body. Kowane step yana ƙara power, kuma kowane step yana ƙara uncertainty. Wannan shi ne darasin da ya dace a riƙe.

Har ila yau yana gyara familiar picture. Cretaceous oceans galibi ana hango su a matsayin duniyar big vertebrate predators da smaller shelled prey. Waɗannan fossils suna nuna cewa wasu soft-bodied invertebrates ba kawai suna ɓoye a ƙarƙashin food web ba. Wataƙila suna compete a upper levels.

Sakamakon visual ne sosai, amma clean story ba “kraken ya kasance real” ba ne. Shi ne cewa large, early finned octopuses sun bar jaws da researchers suka reconstruct gigantic bodies da repeated hard-prey feeding daga gare su — combination da ke yin serious, amma har yanzu inferential, case ga invertebrate top predators a zamanin marine reptiles.

Takaitaccen bayani mai tsabta

Masu bincike sun sake nazarin Cretaceous fossil cephalopod jaws daga Japan da Vancouver Island, kuma sun yi amfani da full-color grinding tomography plus zero-shot AI segmentation don digitally reconstruct hidden jaws a matsayin detailed 3D specimens daga rocks na Japan. Sun sake tsara fossil taxa da dama zuwa species biyu na Nanaimoteuthis, da aka interpret a nan a matsayin early finned octopuses. Fossils sun tura record na finned octopuses zuwa kusan shekaru miliyan 100 da suka wuce. Daga jaw-size scaling, marubutan sun kiyasta total lengths kusan 2.8–7.7 m ga N. jeletzkyi da 6.6–18.6 m ga N. haggarti. Heavy jaw wear — chips, scratches, polish, cracks, da asymmetric edge loss — yana nuna repeated hard-prey crushing da possibly lateralized behavior. Gigantic estimated size plus durophagous carnivory suna goyon bayan interpretation cewa waɗannan octopuses wataƙila sun kasance a top tier na marine food webs. shaida ba ya haɗa whole bodies, exact lengths, identified prey, ko direct measurements na intelligence. Authored research article ba ya propose predation a large marine reptiles.