Ancient 'penis worms' used other creatures' shells, like hermit crabs

‘Penis wormsthat were among Earth’s most fearsome creatures 500 million years ago used other creaturesshells to protect themselves just like hermit crabs do today, studie onthul

  • Researchers led from Yunnan University presented new specimens from China
  • Each were found preserved within the discarded conical shells of hyoliths
  • This behaviour has never been documented or seen in modern ‘penis worms
  • The finding highlights the impacts of predation after the Cambrian Explosion
  • Hermit crabs were far from the first to call other creaturesdiscarded shells their own — fearsomepenis wormsdid the same thing 500 miljoen jaar gelede, a study found.

    Researchers led from Yunnan University presented new specimens recovered from the ‘Guanshan biota’, rock deposits that outcrop around Kunming city in Sjina.

    The Guanshan deposits are famous because they preserve not only shell material, but also the soft tissues that would commonly be lost from the fossil record.

    Four of the phallic creatures — properly known as priapulid worms — were found preserved residing within the conical shells of hyoliths, a long-extinct fossil group.

    Having eliminated other explanations, the team concluded that the ancient worms were forced to take shelter to avoid predators, a conclusion they called ‘surprising’.

    The worms from the Guanshan biota lived not long after theCambrian Explosion‘, a time which saw the rapid diversification and complication of animal life.

    Volgens die navorsers, the findings highlight how key predation was in shaping the ecology and behaviour of animals at this key point in their history.

    Hermiting behaviour has never been observed in modern priapulid worms.

    Hermit crabs weren't the first to call other creatures' discarded shells their own — fearsome ' penis worms ' did the same thing 500 miljoen jaar gelede, 'n studie het bevind. Op die foto: an artist's impression of a priapulid worm squatting in the discarded conical shell of a hyolith

    Hermit crabs weren’t the first to call other creaturesdiscarded shells their own — fearsomepenis wormsdid the same thing 500 miljoen jaar gelede, 'n studie het bevind. Op die foto: an artist’s impression of a priapulid worm squatting in the discarded conical shell of a hyolith

    The Guanshan deposits studied by the team are famous because they preserve not only shell material, but also the soft tissues that would commonly be lost from the fossil record. Op die foto: a fossil of a priapulid worm (Top) poking out of the shell of a hyolith

    The Guanshan deposits studied by the team are famous because they preserve not only shell material, but also the soft tissues that would commonly be lost from the fossil record. Op die foto: a fossil of a priapulid worm (Top) poking out of the shell of a hyolith

    ABOUT ‘PENIS WORMS

    The priapulids — or ‘penis worms— are a phylum of unsegmented marine worms that first evolved some 500 million years ago during the Cambrian.

    Gedurende hierdie periode, they were thought to have been fearsome predators, although the new study shows they were also likely prey in turn.

    Sommige 20 species survive today. They are known to live in mud at relatively shallow depths of up to 300 voete.

    The fossil priapulids studied by Dr Smith and colleagues ranged in length from 0.4–0.7 inches.

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    Volgens die navorsers, each worm and the shell it inhabited corresponded in size — and no worm was found preserved without a shell — suggesting a biological association between the two.

    ‘The worms are always sitting snugly within these same types of shells, in the same position and orientation,’ explained paper author and palaeontologist Martin Smith of the University of Durham.

    ‘The only explanation that made sense was that these shells were their homes —something that came as a real surprise.

    ‘Not long before these organisms existed, there was nothing alive more complex than seaweeds or jellyfish,’ gaan hy voort.

    ‘So it’s mind-boggling that we start to see the complex and dangerous ecologies usually associated with much younger geological periods so soon after the first complex animals arrive on the scene.

    The researchers also considered other explanations for the association between the worms and the shells — such as that the worms used the shells as temporary protection from the hostile conditions that buried and preserved them.

    Egter, hulle het gesê, it is difficult to reconcile this the fact that the worms and shells matched size so well, that the worms were found partially sticking out of the shells, and that no worms were found having failed to find shelter.

    Daarbenewens, die span opgemerk, evidence of emergency sheltering behaviour was not seen among the fossils of the other creatures in the same deposits.

    Volgens die navorsers, each worm and the shell it inhabited corresponded in size — and no worm was found preserved without a shell — suggesting a biological association between the two. Op die foto: one of the fossil worms analysed by the team

    Volgens die navorsers, each worm and the shell it inhabited corresponded in size — and no worm was found preserved without a shell — suggesting a biological association between the two. Op die foto: one of the fossil worms analysed by the team

    Four of the phallic creatures — properly known as priapulid worms — were found preserved residing within the conical shells of hyoliths, a long-extinct fossil group. Op die foto: an artist's impression of a hyoltith shell, albeit one occupied by its original owner

    Four of the phallic creatures — properly known as priapulid worms — were found preserved residing within the conical shells of hyoliths, a long-extinct fossil group. Op die foto: an artist’s impression of a hyoltith shell, albeit one occupied by its original owner

    'The worms are always sitting snugly within these same types of shells, in the same position and orientation,' explained paper author and palaeontologist Martin Smith of the University of Durham. Op die foto: in this fossil, the worm can be seen sticking its head out of the shell

    ‘The worms are always sitting snugly within these same types of shells, in the same position and orientation,’ explained paper author and palaeontologist Martin Smith of the University of Durham. Op die foto: in this fossil, the worm can be seen sticking its head out of the shell

    The ‘hermitinglifestyle is known to have evolved in a diverse range of animal lineages — including not only hermit crabs but also the shrimp-like tanaids and both fauveliopsid and sipunculan worms.

    Most of these creatures prefer to inhabit the discarded shells of gastropods, but some are also known to inhabit the shells and tubes of bristle worms, tusk shells and foraminifera.

    Despite the broad distribution of this practice across the tree of life, egter, it had never previously been seen in any organism living before 170 miljoen jaar gelede, during the so-called Mesozoic Marine Revolution.

    Beginning some 210 miljoen jaar gelede, this ecological ‘arms racesaw sea creatures develop adaptations against the evolution of shell-crushing and -boring predators.

    Die volledige bevindings van die studie is in die tydskrif gepubliseer Current Biology.

    Researchers led from Yunnan University presented new specimens recovered from the 'Guanshan biota', rock deposits that outcrop around Kunming city in China

    Researchers led from Yunnan University presented new specimens recovered from the ‘Guanshan biota’, rock deposits that outcrop around Kunming city in China

    WHAT WAS THE ‘CAMBRIAN EXPLOSION’?

    Scientists have long speculated that a large oxygen spike during the ‘Cambrian Explosionwas key to the development of many animal species.

    The Cambrian Explosion, rondom 541 miljoen jaar gelede, was a period when a wide variety of animals burst onto the evolutionary scene.

    Before about 580 miljoen jaar gelede, most organisms were simple, composed of individual cells occasionally organised into colonies.

    Over the following 70 of 80 miljoen jaar, the rate of evolution accelerated and the diversity of life began to resemble that of today.

    It ended with the Cambrian-Ordovician extinction event, ongeveer 488 miljoen jaar gelede.

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