Введение
Вымерший род кембрийского радиодонта. Автоматический taxobox. | image = Aria et al. 2020 Anomalocaris canadensis head ROMIP 51212. png | image caption = ROMIP 51212, в значительной степени полный образец Anomalocaris canadensis. | image2 = 20191203 Anomalocaris canadensis. png | image2 caption = Реконструкция внешнего вида Anomalocaris canadensis. | fossil range = Ранний – средний кембрий (стадия 3 – гужангский), fossil range|520|499|reference=
Automatic taxobox
| image = Aria et al. 2020 Anomalocaris canadensis head ROMIP 51212. png
| image caption = ROMIP 51212, a largely complete specimen of Anomalocaris canadensis. | image2 = 20191203 Anomalocaris canadensis. png
| image2 caption = Life restoration of Anomalocaris canadensis. | fossil range = Early Cambrian to Middle Cambrian (Stage 3 to Guzhangian), fossil range|520|499|reference=</blockquote>Anomalocaris fossils were first collected in 1886 He found abundant trilobites, along with two unknown specimens. along with 48 more of the unknown specimens. The fifty specimens were examined and described in 1892 by GSC paleontologist Joseph Frederick Whiteaves.</blockquote>In 1928, Danish paleontologist Kai Henriksen proposed that Tuzoia, a Burgess Shale arthropod which was known only from the carapace, represented the missing front half of Anomalocaris. In the same publication in which he named Peytoia, Walcott named Laggania, a taxon that he interpreted as a holothurian. In 1966, the Geological Survey of Canada began a comprehensive revision of the Burgess Shale fossil record, led by Cambridge University paleontologist Harry B. Whittington. Whittington linked the two species, but it took several more years for researchers to realize that the continuously juxtaposed Peytoia, Laggania and frontal appendages (Anomalocaris and "appendage F") actually represented a single group of enormous creatures. compound eyes of Anomalocaris were recovered from a paleontological dig at Emu Bay on Kangaroo Island, Australia, proving that Anomalocaris was indeed an arthropod as had been suspected. The find also indicated that advanced arthropod eyes had evolved very early, before the evolution of jointed legs or hardened exoskeletons. and "A." magnabasis were reassigned to the new genus Houcaris, in the family Tamisiocarididae. In the same year, "A." pennsylvanica was reassigned to the genus Lenisicaris. In 2022, specimen ELRC 20001 that was treated as an unnamed species of Anomalocaris or whole body specimen of A. saron got a new genus, Innovatiocaris. In 2023, "A". kunmingensis was reassigned to the new genus Guanshancaris in the family Amplectobeluidae. Multiple phylogenetic analyses also suggested that "A". briggsi (tamisiocaridid) was not a species of Anomalocaris either, and it was reassigned to the genus Echidnacaris in the family Tamisiocarididae in 2023. In the same 2023 study, a new species of Anomalocaris, A. daleyae, was described based on remains found in the Emu Bay Shale in Australia. and this overlapping allowed the lobes on each side of the body to act as a single "fin", maximizing the swimming efficiency. The construction of a remote controlled model showed this mode of swimming to be intrinsically stable, implying that Anomalocaris would not have needed a complex brain to manage balance while swimming. The body was widest between the third and fifth lobe and narrowed towards the tail, with additional 3 pairs of small flaps on the constricted neck region. Anomalocaris had an unusual disk like mouth known as oral cone. The oral cone was composed of several plates organized triradially. Three of the plates were quite large. Three to four medium sized plates could be found between each of the large plates, and several small plates between them. Most of the plates wrinkled and have scale like tubercles near the mouth opening. The top one, known as a head shield, dorsal carapace or H element, was shaped like an laterally elongated oval, with a distinct rim on the outer edge. The gills of the animal, in the form of long, thin, hair like structures known as lanceolate blades, were arranged in rows forming setal blades. The setal blades were attached by their margin to the top side of the animal, two setal blades per body segment. A divide ran down the middle, separating the gills.
Окаменелости Anomalocaris были впервые собраны в 1886 году. Он обнаружил обилие трилобитов, а также два неизвестных экземпляра, и еще 48 таких же неизвестных экземпляров. Пятьдесят образцов были изучены и описаны в 1892 году палеонтологом Геологической службы Канады (GSC) Джозефом Фредериком Уайтвесом.
Automatic taxobox
| image = Aria et al. 2020 Anomalocaris canadensis head ROMIP 51212. png
| image caption = ROMIP 51212, a largely complete specimen of Anomalocaris canadensis. | image2 = 20191203 Anomalocaris canadensis. png
| image2 caption = Life restoration of Anomalocaris canadensis. | fossil range = Early Cambrian to Middle Cambrian (Stage 3 to Guzhangian), fossil range|520|499|reference=</blockquote>Anomalocaris fossils were first collected in 1886 He found abundant trilobites, along with two unknown specimens. along with 48 more of the unknown specimens. The fifty specimens were examined and described in 1892 by GSC paleontologist Joseph Frederick Whiteaves.</blockquote>In 1928, Danish paleontologist Kai Henriksen proposed that Tuzoia, a Burgess Shale arthropod which was known only from the carapace, represented the missing front half of Anomalocaris. In the same publication in which he named Peytoia, Walcott named Laggania, a taxon that he interpreted as a holothurian. In 1966, the Geological Survey of Canada began a comprehensive revision of the Burgess Shale fossil record, led by Cambridge University paleontologist Harry B. Whittington. Whittington linked the two species, but it took several more years for researchers to realize that the continuously juxtaposed Peytoia, Laggania and frontal appendages (Anomalocaris and "appendage F") actually represented a single group of enormous creatures. compound eyes of Anomalocaris were recovered from a paleontological dig at Emu Bay on Kangaroo Island, Australia, proving that Anomalocaris was indeed an arthropod as had been suspected. The find also indicated that advanced arthropod eyes had evolved very early, before the evolution of jointed legs or hardened exoskeletons. and "A." magnabasis were reassigned to the new genus Houcaris, in the family Tamisiocarididae. In the same year, "A." pennsylvanica was reassigned to the genus Lenisicaris. In 2022, specimen ELRC 20001 that was treated as an unnamed species of Anomalocaris or whole body specimen of A. saron got a new genus, Innovatiocaris. In 2023, "A". kunmingensis was reassigned to the new genus Guanshancaris in the family Amplectobeluidae. Multiple phylogenetic analyses also suggested that "A". briggsi (tamisiocaridid) was not a species of Anomalocaris either, and it was reassigned to the genus Echidnacaris in the family Tamisiocarididae in 2023. In the same 2023 study, a new species of Anomalocaris, A. daleyae, was described based on remains found in the Emu Bay Shale in Australia. and this overlapping allowed the lobes on each side of the body to act as a single "fin", maximizing the swimming efficiency. The construction of a remote controlled model showed this mode of swimming to be intrinsically stable, implying that Anomalocaris would not have needed a complex brain to manage balance while swimming. The body was widest between the third and fifth lobe and narrowed towards the tail, with additional 3 pairs of small flaps on the constricted neck region. Anomalocaris had an unusual disk like mouth known as oral cone. The oral cone was composed of several plates organized triradially. Three of the plates were quite large. Three to four medium sized plates could be found between each of the large plates, and several small plates between them. Most of the plates wrinkled and have scale like tubercles near the mouth opening. The top one, known as a head shield, dorsal carapace or H element, was shaped like an laterally elongated oval, with a distinct rim on the outer edge. The gills of the animal, in the form of long, thin, hair like structures known as lanceolate blades, were arranged in rows forming setal blades. The setal blades were attached by their margin to the top side of the animal, two setal blades per body segment. A divide ran down the middle, separating the gills.
В 1928 году датский палеонтолог Кай Хенриксен предположил, что Tuzoia, артропод из формации Бурджесс-Шейл, известный только по карапаксу, представляет собой недостающую переднюю часть Anomalocaris. В той же публикации, где он описал Peytoia, Уолкотт назвал Laggania, таксон, который он интерпретировал как голотурию. В 1966 году Геологическая служба Канады начала всесторонний пересмотр ископаемой летописи Бурджесс-Шейла под руководством палеонтолога Кембриджского университета Гарри Б. Уиттингтона. Уиттингтон связал эти два вида, но потребовалось еще несколько лет, чтобы исследователи поняли, что постоянно сопоставляемые Peytoia, Laggania и передние придатки (Anomalocaris и "придаток F") на самом деле представляют собой одну группу огромных существ. Составные глаза Anomalocaris были обнаружены при палеонтологических раскопках в заливе Эму на острове Кенгуру, Австралия, что подтвердило предположение о том, что Anomalocaris действительно является артроподом. Эта находка также показала, что сложные глаза артропод эволюционировали очень рано, до появления суставных ног или затвердевшего экзоскелета. В том же году "A." magnabasis был отнесен к новому роду Houcaris, в семействе Tamisiocarididae. В том же году "A." pennsylvanica был отнесен к роду Lenisicaris. В 2022 году образец ELRC 20001, ранее считавшийся неописанным видом Anomalocaris или полным экземпляром A. saron, получил новый род Innovatiocaris. В 2023 году "A." kunmingensis был отнесен к новому роду Guanshancaris в семействе Amplectobeluidae. Многочисленные филогенетические анализы также показали, что "A." briggsi (tamisiocaridid) также не является видом Anomalocaris, и в 2023 году он был отнесен к роду Echidnacaris в семействе Tamisiocarididae. В том же исследовании 2023 года был описан новый вид Anomalocaris, A. daleyae, на основе останков, найденных в сланце Эму-Бэй в Австралии. Перекрытие лопастей с каждой стороны тела позволяло им функционировать как единое "плавцовое весло", максимизируя эффективность плавания. Создание дистанционно управляемой модели показало, что этот способ плавания по своей сути стабилен, что подразумевает, что Anomalocaris не нуждался в сложном мозге для поддержания равновесия во время плавания. Тело было наиболее широким между третьей и пятой долями и сужалось к хвосту, с дополнительными тремя парами небольших лопастей в области суженной шеи. Anomalocaris обладал необычным дискообразным ртом, известным как оральный конус. Оральный конус состоял из нескольких пластин, расположенных трирадиально. Три пластины были довольно большими, между каждой из больших пластин находилось три-четыре пластины среднего размера, а между ними – несколько маленьких пластин. Большинство пластин были морщинистыми и имели чешуйчатые бугорки вблизи ротового отверстия. Верхняя пластина, известная как головной щит, спинной карапакс или элемент H, имела форму боковой удлиненной овальной формы с отчетливым краем по внешнему краю. Жабры животного, в виде длинных, тонких, волосовидных структур, известных как ланцетовидные лезвия, были расположены рядами, образуя щетинковидные лезвия. Щетинковидные лезвия крепились своим краем к верхней стороне тела, по два лезвия на каждый сегмент тела. Посередине проходил разделитель, разделяющий жабры.
Automatic taxobox
| image = Aria et al. 2020 Anomalocaris canadensis head ROMIP 51212. png
| image caption = ROMIP 51212, a largely complete specimen of Anomalocaris canadensis. | image2 = 20191203 Anomalocaris canadensis. png
| image2 caption = Life restoration of Anomalocaris canadensis. | fossil range = Early Cambrian to Middle Cambrian (Stage 3 to Guzhangian), fossil range|520|499|reference=</blockquote>Anomalocaris fossils were first collected in 1886 He found abundant trilobites, along with two unknown specimens. along with 48 more of the unknown specimens. The fifty specimens were examined and described in 1892 by GSC paleontologist Joseph Frederick Whiteaves.</blockquote>In 1928, Danish paleontologist Kai Henriksen proposed that Tuzoia, a Burgess Shale arthropod which was known only from the carapace, represented the missing front half of Anomalocaris. In the same publication in which he named Peytoia, Walcott named Laggania, a taxon that he interpreted as a holothurian. In 1966, the Geological Survey of Canada began a comprehensive revision of the Burgess Shale fossil record, led by Cambridge University paleontologist Harry B. Whittington. Whittington linked the two species, but it took several more years for researchers to realize that the continuously juxtaposed Peytoia, Laggania and frontal appendages (Anomalocaris and "appendage F") actually represented a single group of enormous creatures. compound eyes of Anomalocaris were recovered from a paleontological dig at Emu Bay on Kangaroo Island, Australia, proving that Anomalocaris was indeed an arthropod as had been suspected. The find also indicated that advanced arthropod eyes had evolved very early, before the evolution of jointed legs or hardened exoskeletons. and "A." magnabasis were reassigned to the new genus Houcaris, in the family Tamisiocarididae. In the same year, "A." pennsylvanica was reassigned to the genus Lenisicaris. In 2022, specimen ELRC 20001 that was treated as an unnamed species of Anomalocaris or whole body specimen of A. saron got a new genus, Innovatiocaris. In 2023, "A". kunmingensis was reassigned to the new genus Guanshancaris in the family Amplectobeluidae. Multiple phylogenetic analyses also suggested that "A". briggsi (tamisiocaridid) was not a species of Anomalocaris either, and it was reassigned to the genus Echidnacaris in the family Tamisiocarididae in 2023. In the same 2023 study, a new species of Anomalocaris, A. daleyae, was described based on remains found in the Emu Bay Shale in Australia. and this overlapping allowed the lobes on each side of the body to act as a single "fin", maximizing the swimming efficiency. The construction of a remote controlled model showed this mode of swimming to be intrinsically stable, implying that Anomalocaris would not have needed a complex brain to manage balance while swimming. The body was widest between the third and fifth lobe and narrowed towards the tail, with additional 3 pairs of small flaps on the constricted neck region. Anomalocaris had an unusual disk like mouth known as oral cone. The oral cone was composed of several plates organized triradially. Three of the plates were quite large. Three to four medium sized plates could be found between each of the large plates, and several small plates between them. Most of the plates wrinkled and have scale like tubercles near the mouth opening. The top one, known as a head shield, dorsal carapace or H element, was shaped like an laterally elongated oval, with a distinct rim on the outer edge. The gills of the animal, in the form of long, thin, hair like structures known as lanceolate blades, were arranged in rows forming setal blades. The setal blades were attached by their margin to the top side of the animal, two setal blades per body segment. A divide ran down the middle, separating the gills.
Диета
Интерпретация Anomalocaris как активного хищника широко распространена на протяжении всей истории исследований. В случае с A. canadensis, его выдающийся размер среди фауны Бурджесс-Шейл также делает его одним из первых известных высших хищников. Некоторые кембрийские трилобиты были обнаружены с круглыми или W-образными "следами укусов", которые были идентифицированы как имеющие ту же форму, что и ротовые части Peytoia (ранее ошибочно идентифицированные как принадлежащие Anomalocaris).
Отсутствие износа на ротовых частях радиодонтов предполагает, что они не вступали в регулярный контакт с минерализованными панцирями трилобитов, и, возможно, лучше приспособлены для питания более мелкими, мягкотелыми организмами путем высасывания, поскольку они могли бы разрушиться при использовании против брони трилобитов. Трехмерное моделирование различных передних придатков радиодонтов также указывает на то, что A. canadensis более способен охотиться на более мелких (2–5 см в диаметре), активных, мягкотелых животных (например, vetulicolian; свободноплавающих членистоногих, таких как изоксиды и гименокарины; Nectocaris). В сланцевом месторождении Берджесс Anomalocaris чаще встречается в более древних слоях, особенно в трелобитовых породах горы Стивен. Однако в более молодых слоях, таких как филлоподовый горизонт, Anomalocaris мог достигать гораздо больших размеров; примерно в два раза больше, чем его более древние родственники из трелобитовых пород. Эти редкие гигантские экземпляры ранее относили к отдельному виду, Anomalocaris gigantea; однако обоснованность этого вида была поставлена под сомнение в современном Китае. Anomalocaris daleyae (Emu Bay Shale) обитала в сопоставимой среде обитания – в мелководных тропических водах кембрийской Австралии, но таксономически маловероятно, что она является членом Anomalocaris или даже Anomalocarididae.