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Descoberta de pesquisadores brasileiros e norte-americanos pode mudar a classificação de duas espécies, que parecem estar mais próximas das águas-vivas do que se pensava (Pachycerianthus magnus; foto: Sérgio Stampar)

Anêmona-de-tubo tem o maior genoma mitocondrial entre os animais

13 de maio de 2019

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André Julião | Agência FAPESP – Com apenas 15 centímetros de comprimento, a anêmona-de-tubo Isarachnanthus nocturnus é a espécie animal com o maior genoma mitocondrial já observado. 

Foram sequenciados, ao todo, 80.923 pares de base – os blocos que compõem o DNA. Nos humanos, o genoma encontrado na mitocôndria, organela responsável por gerar energia para a célula, é composto por 17 mil pares de base.

Os dados são de um artigo publicado recentemente na revista Scientific Reports.

A pesquisa foi coordenada por Sérgio Nascimento Stampar, professor da Faculdade de Ciências e Letras da Universidade Estadual Paulista (Unesp), em Assis. Contou com apoio da FAPESP por meio do projeto “Evolução e diversidade de Ceriantharia (Cnidaria)”, na modalidade Auxílio Regular, e do programa SPRINT, em convênio com a Universidade da Carolina do Norte, em Charlotte, nos Estados Unidos.

Como explicou o pesquisador, o genoma mitocondrial é mais simples do que o nuclear, cujo sequenciamento nessa anêmona-de-tubo ainda não foi feito. O DNA nuclear humano, por exemplo, é composto por 3 bilhões de pares de base.

Outra descoberta divulgada no artigo é que a I. nocturnus e a Pachycerianthus magnus (77.828 pares de base), outra espécie estudada pelo grupo de Assis, têm genomas lineares como o das águas-vivas (Medusozoa), e não circulares como o de outras espécies do seu grupo (Anthozoa) e o da maioria dos animais.

A Isarachnanthus nocturnus é encontrada da costa da Patagônia, na Argentina, até os Estados Unidos, enquanto a Pachycerianthus magnus vive nos mares que circundam a ilha de Taiwan, na Ásia. Ambas habitam águas com no máximo 15 metros de profundidade.

“O tamanho do genoma mitocondrial da I. nocturnus chega a ser quase cinco vezes maior do que o humano. 

Temos a tendência de achar que somos mais complexos molecularmente, mas na verdade o nosso genoma foi mais ‘filtrado’ ao longo da evolução. Provavelmente, manter esse genoma gigante é muito mais custoso em termos de gasto energético”, explicou Stampar.

Mais surpreendente do que o tamanho do genoma das duas espécies de anêmona, no entanto, foram o formato e as sequências de genes encontrados.

Por serem espécies próximas, esperava-se uma sequência parecida de genes. A americana, no entanto, tem cinco cromossomos, enquanto a taiwanesa tem oito, com genes totalmente diferentes entre si. Uma variação antes vista apenas em águas-vivas, esponjas e alguns crustáceos.

“O DNA mitocondrial humano é mais parecido com o de um peixe ósseo na organização do que o dessas duas anêmonas-de-tubo entre si”, disse Stampar.

Litoral paulista e mar da China Meridional

Para chegar aos resultados, os pesquisadores capturaram animais em São Sebastião, no litoral de São Paulo, e no mar da China Meridional, onde fica a ilha de Taiwan. O genoma mitocondrial foi sequenciado a partir de pequenos pedaços dos tentáculos dos animais.

Os genomas das duas espécies disponíveis em bancos de dados até então eram incompletos, pela grande dificuldade de sequenciá-los. Após a conclusão do trabalho, os pesquisadores disponibilizaram os genomas no GenBank, banco de dados genéticos mantido pelo National Institutes of Health (NIH), dos Estados Unidos.

Outra dificuldade para fazer o sequenciamento foi o fato de esses animais serem extremamente difíceis de coletar, por conta de seu comportamento fugidio. Basta qualquer possível ameaça para que se escondam dentro do tubo que os diferencia das anêmonas regulares, tornando impossível a captura.

“É preciso cavar em volta, às vezes até um metro de profundidade, e tampar a parte do tubo que fica por baixo da areia. Isso tudo debaixo d’água, carregando equipamento de mergulho. Se não fazemos desse jeito, ele se esconde na parte soterrada do tubo, o que impossibilita a coleta”, disse o pesquisador. Graças ao apoio do programa SPRINT da FAPESP, Stampar e Marymegan Daly, sua colega de pesquisa na Ohio State University, estabeleceram parceria com Adam Reitzel e seu pós-doutorando na época, Jason Macrander, da Universidade da Carolina do Norte, em Charlotte, Estados Unidos. Atualmente, Macrander é professor no Florida Southern College. 

Reitzel e Macrander sãos especializados em técnicas de bioinformática para filtragem de dados genômicos, ou seja, transformar milhões de pequenas sequências obtidas no sequenciamento em uma só. Dessa forma, eles conseguiram montar o genoma mitocondrial completo das duas espécies.

“É uma técnica em que são sequenciados pedaços do genoma, que vão se ligando até formarem um círculo. O problema é que isso só funciona com genomas circulares. Como nunca surgia a peça para fechar esse círculo, nos demos conta de que só podia ser um genoma linear como o das águas-vivas”, disse Stampar.

A descoberta abre espaço para uma eventual reclassificação das espécies dentro dos Cnidários (águas-vivas, anêmonas, medusas e corais). Aparentemente, as anêmonas-de-tubo estudadas formam um grupo à parte, independente dos corais e outras anêmonas, e contam com alguma similaridade com as águas-vivas.

Porém, ainda são necessários mais dados para uma conclusão definitiva, que pode vir com o sequenciamento do genoma nuclear das espécies, algo que o grupo de Stampar pretende realizar até o fim deste ano.

O artigo Linear Mitochondrial Genome in Anthozoa (Cnidaria): A Case Study in Ceriantharia (doi: 10.1038/s41598-019-42621-z), de Sérgio N. Stampar, Michael B. Broe, Jason Macrander, Adam M. Reitzel, Mercer R. Brugler e Marymegan Daly, pode ser lido em: www.nature.com/articles/s41598-019-42621-z.

Oldest Known Jellyfish Fossils Found

By Andrea Thompson | October 30, 2007 01:31pm ET

Fossil evidence of jellyfish dates back to the Cambrian Period, 500 million years ago. This fossil jellyfish shows similarity to the modern jellyfish, Cunina (right). It was one of four different types of jellyfish dated back to the Cambrian by researchers in 2007. These ancient jellyfish showed the same complexity as modern jellyfish, meaning they either developed rapidly 500 million years ago, or today’s varieties are much older.

Credit: Fossil photo by B. Lieberman. Cunina photo by K. Raskoff, copyright.

The oldest known fossils of jellyfish have been found in rocks in Utah that are more than 500 million years old, a new study reports.

The fossils are an unusual discovery because soft-bodied creatures, such as jellyfish, rarely survive in the fossil record, unlike animals with hard shells or bones.
"The fossil record is biased against soft-bodied life forms such as jellyfish, because they leave little behind when they die," said study member Bruce Lieberman of the University of Kansas.
These jellyfish left their lasting imprint because they were deposited in fine sediment, rather than coarse sand. The film that the jellyfish left behind shows a clear picture, or "fossil snapshot," of the animals.
"You can see a distinct bell-shape, tentacles, muscle scars and possibly even the gonads," said study team member Paulyn Cartwright, also of KU.

The rich detail of the fossils allowed the team to compare the cnidarian (the phylum to which jellyfish, coral and sea anemones belong) fossils to modern jellyfish. The comparison confirmed that the fossils were, in fact, jellyfish and pushed the earliest known occurrence of definitive jellyfish back from 300 million to 505 million years ago.

The fossils also offer insights into the rapid species diversification that occurred during the Cambrian radiation, which began around 540 million years ago and when most animal groups start to show up in the fossil record, Lieberman said.

The complexity of these early jellyfish seems to suggest that either the complexity of modern jellyfish developed rapidly about 500 million years ago, or that jellyfish are even older and developed long before that time.

Desert Fossils Reveal 540-Million-Year-Old Jellyfish 'Graveyard'

By Mindy Weisberger, Senior Writer | August 7, 2017 06:49am ET

Walk across a beach's wet sand, and you'll leave behind imprints that briefly hold the shape of your feet before blurring and falling apart.

But 540 million years ago, seaside sand contained densely packed microbial communities, which created a gooey glue that was excellent for preserving impressions of ocean creatures left high and dry by retreating waves.

And on a long-gone seashore in what is now arid Death Valley, sticky sand retained impressions of the oldest known example of a jellyfish stranding, saving a fossilized snapshot of Cambrian period marine life that researchers excavated and described in a new study. [Cambrian Creatures Gallery: Photos of Primitive Sea Life]

The ancient jellyfish were preserved in a slab of sandstone found in southeastern California. Scientists identified 13 of these oval specimens on the rocky surface, ranging from 1.2 to 8.3 inches (3 to 21 centimeters) in diameter. The fossils were lighter than the rock surrounding them, and they varied not only in size but also their style of preservation. Some included convex, circular ridges; others held concave rings around a convex interior; and several were fossilized as more pronounced, rounded mounds, the scientists wrote in the study.

In one jellyfish specimen, shapes of some of the animal's body parts were still faintly visible. Additional marks in the rock around the fossilized jellyfish hinted at the movements of ancient currents, which may have pushed and distorted the bodies of the stranded jellyfish prior to fossilization. Other marks might have been made by a stranded jellyfish's attempts to move back into the water, according to the study authors.

Unique conditions for fossil formation

Ancient, soft-bodied animals are exceedingly rare in the fossil record, compared with animals with robust skeletons or shells, the study authors wrote. But a unique combination of environmental conditions can preserve even jellyfish in surprising detail, study lead author and geologist Aaron Sappenfield told Live Science.

Illustrations set the scene for a jellyfish stranding during the Cambrian period. A group of jellyfish were swept toward the shore and were beached by the receding tide.

Credit: Aaron Sappenfield/University of California, Riverside

Jellyfish that wash up on beaches today are frequently eaten by scavenging birds and crustaceans, Sappenfield said. But during the Cambrian period, when marine life was bountiful and diverse, there were no large terrestrial scavengers to pick at the jellies' carcasses. If they became stranded, chances were good that their remains would stay in one place long enough to fossilize, he said.
However, the jellies' preservation was equally dependent on the gummy, microbe-rich sand that they stranded themselves on, which was also a characteristic of the Cambrian period, Sappenfield said.
"A jellyfish lands on the beach — that big, wet sack settles in the sand — and you get this nice impression with really high resolution because of that binding agent," he said.

This jellyfish was likely buried in sand after it became stranded; its body collapsed, and the carcass was preserved in the microbe-rich sediment.

Credit: Aaron Sappenfield/University of California, Riverside

Most of the known fossils of mass jellyfish strandings date to the Cambrian, likely because that period presented these unique conditions — few scavengers, and sticky sand — that enabled fossilization in an organism that was very difficult to preserve, Sappenfield told Live Science.

Solving an ancient puzzle

Early Cambrian fossils such as these are also helping paleontologists investigate a long-standing mystery about a group of bizarre marine organisms known collectively as the Ediacaran biota, which appeared around 575 million years ago and abruptly disappeared from the fossil record around the beginning of the Cambrian period, about 540 million years ago, Sappenfield said.

"Trying to compare types of fossils preserved on either side of the boundary is a very important step, to say if they vanished because preservation conditions didn't favor them, or because of another reason, such as a mass extinction," he explained.

This oval impression is all that remains of a jellyfish that washed up on a beach 540 million years ago, part of a mass stranding in what is now Death Valley.

Credit: Aaron Sappenfield/University of California, Riverside

These "boundary" fossils could offer clues about what factors may have led to dramatic shifts like those that occurred for the Ediacaran biota. And with that information, scientists could better understand how ecosystems today may be affected by changing conditions, such as those driven by human activity, Sappenfield said.

"Minor perturbances to ecology and how global ecosystems behave can manifest in very significant changes in the way the biosphere [places on Earth that harbor life] is structured," he said.
The findings were published online in the July 2017 issue of the journal Geological Magazine.

Bela invasora do mar

10 de maio de 2016

Karina Toledo  |  Agência FAPESP – O nome pomposo foi escolhido em homenagem a duas personagens da mitologia grega: Cassiopeia, a rainha da Etiópia que com sua vaidade e arrogância teria provocado a ira das Nereidas, e Andrômeda, sua filha, oferecida em sacrifício a um monstro marinho enviado pelo deus Nereu para castigar o reino etíope.

Pesquisadores confirmam a presença de medusas da espécie Cassiopea andromeda no litoral brasileiro. Análises sugerem que o animal teria emigrado do mar Vermelho para as Américas durante as grandes navegações (foto: Sergio Stampar)

Reservada, Cassiopea andromeda não é como outras espécies de água-viva que saem por aí nadando em busca de comida e de parceiros sexuais. Ela procura um canto para chamar de seu e por ali permanece, de ponta-cabeça, durante boa parte da vida. Mas é exigente: o local deve ter água calma, rasa, quente e transparente. É também de uma grande beleza.
Até pouco tempo atrás, os cientistas acreditavam que essa espécie originária do mar Vermelho não ocorria no litoral brasileiro – que, de maneira geral, não lhe oferece as condições ideais de sobrevivência. Mas sua presença na forma adulta – de medusa – foi pela primeira vez confirmada no país em um estudo apoiado pela FAPESP e publicado recentemente no Journal of the Marine Biological Association of the United Kingdom.
Análises genéticas descritas no artigo sugerem que a presença de Cassiopea andromeda em águas brasileiras é bem mais antiga do que se poderia imaginar.

Uma das hipóteses é que ela teria vindo para as Américas na época das grandes navegações e, inicialmente, se instalado na região da Flórida e do Caribe. Em seguida, aproveitando o intenso fluxo de caravelas que cruzavam o continente naquele período, teria alcançado o Havaí e o litoral sul-americano.
“Nossa teoria é que, na forma de pólipo [a primeira fase de seu ciclo de vida], a espécie teria grudado em alguma embarcação antiga e, assim, chegado ao Brasil”, relatou Sérgio Nascimento Stampar, professor da Universidade Estadual Paulista (Unesp) em Assis e coautor do artigo.
Assim como ocorre com outras espécies de águas-vivas, explicou o pesquisador, o ciclo de vida de Cassiopea andromeda é dividido em duas fases: pólipo e medusa.

As medusas adultas se reproduzem de forma sexuada e geram os pólipos – organismos sésseis (que não se movimentam voluntariamente e vivem fixos a rochas, conchas ou outras estruturas sólidas), com no máximo 5 milímetros de tamanho, que são considerados imortais pelos cientistas.
“Os pólipos podem se reproduzir de forma assexuada e dar origem a novos pólipos com a mesma carga genética ou, se as condições do meio forem favoráveis, podem brotar e se transformar em medusas. Na fase adulta, o animal pode alcançar entre 30 e 40 centímetros de diâmetro, o tamanho de uma pizza”, disse Stampar.
A presença de pólipos da Cassiopea andromeda já havia sido identificada no Brasil em 1999, no Centro de Biologia Marinha da Universidade de São Paulo (CEBIMar/USP).
“Não achávamos que encontraríamos a forma adulta em nosso litoral porque elas preferem condições parecidas com as existentes no Caribe: águas claras, que permitem a passagem da luz do sol. Essa dependência da energia solar se deve ao fato de que a espécie vive em associação com um organismo simbionte, um protista dinoflagelado que faz fotossíntese e transfere parte do carbono gerado para a medusa em troca de acolhida e proteção”, disse Stampar.

Além de ficar com parte da energia produzida pelo inquilino, a Cassiopea andromeda também se alimenta de pequenos animais que habitam o sedimento marinho. Para isso, ela permanece de ponta-cabeça e bate contra o fundo do oceano para levantar uma nuvem de petiscos com a qual se delicia.

O professor André Carrara Morandini, chefe do Departamento de Zoologia do Instituto de Biociências (IB) da USP e autor principal do artigo, contou que recebeu em 2008 fotos de uma população de águas-vivas bastante peculiar que havia aparecido no canal Itajuru, na cidade de Cabo Frio (RJ).
“Na época, eu trabalhava em um campus da Universidade Federal do Rio de Janeiro (UFRJ) próximo de Cabo Frio e me pediram ajuda para identificar a espécie até então desconhecida. Sabíamos que pertencia ao gênero Cassiopea, mas este abrange 12 diferentes espécies e não conseguíamos definir claramente em qual delas os animais se encaixavam”, disse.

Por meio das análises genéticas, o grupo confirmou que se tratava de Cassiopea andromeda. Ao comparar as amostras coletadas no Brasil com dados de bancos públicos, como o www.ncbi.nlm.nih.gov/genbank, notaram que o material genético era idêntico ao de animais encontrados no Caribe e na região do mar Vermelho.
“Começamos, então, a discutir como essas águas-vivas teriam se deslocado por distâncias tão grandes e concluímos que vieram durante as grandes navegações. Com técnicas de datação molecular, modelos que calculam a taxa de mutação de uma espécie, foi possível estimar quando essa migração teria ocorrido. Mas ainda não sabemos se ela migrou gradativamente do Caribe para o Brasil ou se houve uma segunda introdução independente no continente americano”, disse Morandini.

Desaparecimento repentino
Por algum motivo que os pesquisadores ainda desconhecem, a população de medusas encontrada em Cabo Frio se desenvolveu intensamente entre os anos de 2008 e 2009 e depois entrou em declínio. No auge populacional, os pesquisadores contaram mais de 2 mil indivíduos em uma área de 200 metros quadrados. Entre 2012 e 2013, todos desapareceram.
Os pólipos da espécie, no entanto, continuam por lá e podem ser encontrados em diversas partes do litoral brasileiro.

“Esse desaparecimento repentino das medusas é um indício de que se trata de uma espécie não nativa, ou seja, introduzida ou invasora. Outra evidência é que, nessa população de Cabo Frio, todos os indivíduos eram machos”, disse Morandini.
No artigo, o grupo discute o risco ambiental representado por espécies invasoras, que na ausência de predadores naturais podem dominar uma determinada região e comprometer a sobrevivência de outras espécies, gerando desequilíbrio ecológico.
“Em algumas partes do mundo, como no Japão, a explosão populacional de águas-vivas é um problema sério. Elas são peçonhentas e podem matar peixes e outros organismos marinhos que com elas tiverem contato – prejudicando a piscicultura e a pesca. Como a Cassiopea andromeda é uma espécie introduzida no Brasil, isso pode ocorrer a qualquer momento, caso ela se adapte à região”, disse Stampar.
Morandini, porém, acredita que os riscos são pequenos. “A espécie poderia, talvez, causar algum desequilíbrio em uma região mais fechada, como uma baía ou uma lagoa. Como são animais com mobilidade bastante reduzida, dificilmente vão se dispersar por grandes distâncias. Não acredito que haveria um grande impacto no ambiente que chegasse a prejudicar os humanos”, avaliou.

As análises que deram origem ao artigo foram feitas no âmbito de um Projeto Temático coordenado pelo professor do IB-USP Antonio Carlos Marques, no âmbito do Programa FAPESP de Pesquisas em Caracterização, Conservação, Restauração e Uso Sustentável da Biodiversidade (BIOTA-FAPESP).

O artigo All non-indigenous species were introduced recently? The case study of Cassiopea (Cnidaria: Scyphozoa) in Brazilian waters (doi: 10.1017/S0025315416000400) pode ser lido em journals.cambridge.org/action/displayAbstract?fromPage=online&aid=10266270&fileId=S0025315416000400.

A newly-identified species of spike-covered worm with legs, which lived 500 million years ago, was one of the first animals on Earth to develop armour for protection.

Collins’ Monster sort of looks like Hallucigenia on steroids

Javier Ortega-Hernández

A new species of ‘super-armoured’ worm, a bizarre, spike-covered creature which ate by filtering nutrients out of seawater with its feather-like front legs, has been identified by palaeontologists. The creature, which lived about half a billion years ago, was one of the first animals on Earth to develop armour to protect itself from predators and to use such a specialised mode of feeding.
The creature, belonging to a poorly understood group of early animals, is also a prime example of the broad variety of form and function seen in the early evolutionary history of a modern group of animals that, today, are rather homogenous. The results, from researchers at the University of Cambridge and Yunnan University in China, are published today (29 June) in the journal PNAS.
The creature has been named Collinsium ciliosum, or Hairy Collins’ Monster, named for the palaeontologist Desmond Collins, who discovered and first illustrated a similar Canadian fossil in the 1980s. The newly-identified species lived in what is now China during the Cambrian explosion, a period of rapid evolutionary development around half a billion years ago, when most major animal groups first appear in the fossil record.

A detailed analysis of its form and evolutionary relationships indicates that the Chinese Collins’ Monster is a distant early ancestor of modern velvet worms, or onychophorans, a small group of squishy animals resembling legged worms that live primarily in tropical forests around the world.
“Modern velvet worms are all pretty similar in terms of their general body organisation and not that exciting in terms of their lifestyle,” said Dr Javier Ortega-Hernández of Cambridge’s Department of Earth Sciences, one of the paper’s lead authors. “But during the Cambrian, the distant relatives of velvet worms were stunningly diverse and came in a surprising variety of bizarre shapes and sizes.”

The pattern of diverse ancestors leading to relatively unvaried modern relatives has been observed in other groups in the fossil record, including sea lilies (crinoids) and lamp shells (brachiopods). However, this is the first time that this evolutionary pattern has been observed in a mostly soft-bodied group.
Ortega-Hernández and his colleagues identified a remarkably well-preserved fossil from southern China, which included details of the full body organisation, the digestive tract, even down to a delicate coat of hair-like structures on the front end. Their analysis found it to be a new species – an eccentric ancestor of an otherwise straight-laced group.

The Chinese Collins’ Monster had a soft and squishy body, six pairs of feather-like front legs, and nine pairs of rear legs ending in claws. Since the clawed rear legs were not well-suited for walking along the muddy ocean floor, it is likely that Collinsium eked out an existence by clinging onto sponges or other hard substances by its back claws, while sieving out its food with its feathery front legs. Some modern animals, including bamboo shrimp, feed in a similar way, capturing passing nutrients with their fan-like forearms.
Given its sedentary lifestyle and soft body, the Chinese Collins’ Monster would have been a sitting duck for any predators, so it developed an impressive defence mechanism: as many as 72 sharp and pointy spikes of various sizes covering its body, making it one of the earliest soft-bodied animals to develop armour for protection.
The Chinese Collins’ Monster resembles Hallucigenia, another otherworldly Cambrian fossil, albeit one which has been the subject of much more study.
“Both creatures are lobopodians, or legged worms, but the Collins’ Monster sort of looks like Hallucigenia on steroids,” said Ortega-Hernández. “It had much heavier armour protecting its body, with up to five pointy spines per pair of legs, as opposed to Hallucigenia’s two. Unlike Hallucigenia, the limbs at the front of Collins’ Monster’s body were also covered with fine brushes or bristles that were used for a specialised type of feeding from the water column.”
The spines along Collinsium’s back had a cone-in-cone construction, similar to Russian nesting dolls. This same construction has also been observed in the closely-related Hallucigenia and the claws in the legs of velvet worms, making both Collinsium and Hallucigenia distant ancestors of modern onychophorans. According to Ortega-Hernández, “There are at least four more species with close family ties to the Collins’ Monster, which collectively form a group known as Luolishaniidae. Fossils of these creatures are hard to come by and mostly fragmentary, so the discovery of Collinsium greatly improves our understanding of these bizarre organisms.”
The fossil was found in the Xiaoshiba deposit in southern China, a site which is less-explored than the larger Chengjiang deposit nearby, but has turned up fascinating and well-preserved specimens from this key period in Earth’s history.
“Animals during the Cambrian were incredibly diverse, with lots of interesting behaviours and modes of living,” said Ortega-Hernández. “The Chinese Collins’ Monster was one of these evolutionary ‘experiments’ – one which ultimately failed as they have no living direct ancestors – but it’s amazing to see how specialised many animals were hundreds of millions of years ago. At its core, the study of the fossil record seeks answers about the evolution of life on Earth that can only be found in deep time. All the major biological events responsible for shaping the world we inhabit, such as the origin of life, the early diversification of animals, or the establishment of the modern biosphere, are intimately linked to the complex geological history of our planet.”
The research was funded by the National Natural Science Foundation of China, Emmanuel College, Cambridge, and the Templeton World Charity Foundation.

Spiky monsters: new species of ‘super-armoured’ worm discovered - See more at: http://www.cam.ac.uk/research/news/spiky-monsters-new-species-of-super-armoured-worm-discovered#sthash.8IxqS2fW.dpuf

Spiky monsters: new species of ‘super-armoured’ worm discovered - See more at: http://www.cam.ac.uk/research/news/spiky-monsters-new-species-of-super-armoured-worm-discovered#sthash.8IxqS2fW.dpuf

Spiky monsters: new species of ‘super-armoured’ worm discovered - See more at: http://www.cam.ac.uk/research/news/spiky-monsters-new-species-of-super-armoured-worm-discovered#sthash.8IxqS2fW.dpuf

Spiky monsters: new species of ‘super-armoured’ worm discovered - See more at: http://www.cam.ac.uk/research/news/spiky-monsters-new-species-of-super-armoured-worm-discovered#sthash.8IxqS2fW.dpuf

Spiky monsters: new species of ‘super-armoured’ worm discovered - See more at: http://www.cam.ac.uk/research/news/spiky-monsters-new-species-of-super-armoured-worm-discovered#sthash.8IxqS2fW.dpuf

Spiky monsters: new species of ‘super-armoured’ worm discovered

• Research
• News

• Spiky monsters: new species of ‘super-armoured’ worm discovered

A newly-identified species of spike-covered worm with legs, which lived 500 million years ago, was one of the first animals on Earth to develop armour for protection.

Collins’ Monster sort of looks like Hallucigenia on steroids

Javier Ortega-Hernández

A new species of ‘super-armoured’ worm, a bizarre, spike-covered creature which ate by filtering nutrients out of seawater with its feather-like front legs, has been identified by palaeontologists. The creature, which lived about half a billion years ago, was one of the first animals on Earth to develop armour to protect itself from predators and to use such a specialised mode of feeding.
The creature, belonging to a poorly understood group of early animals, is also a prime example of the broad variety of form and function seen in the early evolutionary history of a modern group of animals that, today, are rather homogenous. The results, from researchers at the University of Cambridge and Yunnan University in China, are published today (29 June) in the journal PNAS.
The creature has been named Collinsium ciliosum, or Hairy Collins’ Monster, named for the palaeontologist Desmond Collins, who discovered and first illustrated a similar Canadian fossil in the 1980s. The newly-identified species lived in what is now China during the Cambrian explosion, a period of rapid evolutionary development around half a billion years ago, when most major animal groups first appear in the fossil record.
A detailed analysis of its form and evolutionary relationships indicates that the Chinese Collins’ Monster is a distant early ancestor of modern velvet worms, or onychophorans, a small group of squishy animals resembling legged worms that live primarily in tropical forests around the world.
“Modern velvet worms are all pretty similar in terms of their general body organisation and not that exciting in terms of their lifestyle,” said Dr Javier Ortega-Hernández of Cambridge’s Department of Earth Sciences, one of the paper’s lead authors. “But during the Cambrian, the distant relatives of velvet worms were stunningly diverse and came in a surprising variety of bizarre shapes and sizes.”
The pattern of diverse ancestors leading to relatively unvaried modern relatives has been observed in other groups in the fossil record, including sea lilies (crinoids) and lamp shells (brachiopods). However, this is the first time that this evolutionary pattern has been observed in a mostly soft-bodied group.
Ortega-Hernández and his colleagues identified a remarkably well-preserved fossil from southern China, which included details of the full body organisation, the digestive tract, even down to a delicate coat of hair-like structures on the front end. Their analysis found it to be a new species – an eccentric ancestor of an otherwise straight-laced group.
The Chinese Collins’ Monster had a soft and squishy body, six pairs of feather-like front legs, and nine pairs of rear legs ending in claws. Since the clawed rear legs were not well-suited for walking along the muddy ocean floor, it is likely that Collinsium eked out an existence by clinging onto sponges or other hard substances by its back claws, while sieving out its food with its feathery front legs. Some modern animals, including bamboo shrimp, feed in a similar way, capturing passing nutrients with their fan-like forearms.
Given its sedentary lifestyle and soft body, the Chinese Collins’ Monster would have been a sitting duck for any predators, so it developed an impressive defence mechanism: as many as 72 sharp and pointy spikes of various sizes covering its body, making it one of the earliest soft-bodied animals to develop armour for protection.
The Chinese Collins’ Monster resembles Hallucigenia, another otherworldly Cambrian fossil, albeit one which has been the subject of much more study.
“Both creatures are lobopodians, or legged worms, but the Collins’ Monster sort of looks like Hallucigenia on steroids,” said Ortega-Hernández. “It had much heavier armour protecting its body, with up to five pointy spines per pair of legs, as opposed to Hallucigenia’s two. Unlike Hallucigenia, the limbs at the front of Collins’ Monster’s body were also covered with fine brushes or bristles that were used for a specialised type of feeding from the water column.”
The spines along Collinsium’s back had a cone-in-cone construction, similar to Russian nesting dolls. This same construction has also been observed in the closely-related Hallucigenia and the claws in the legs of velvet worms, making both Collinsium and Hallucigenia distant ancestors of modern onychophorans. According to Ortega-Hernández, “There are at least four more species with close family ties to the Collins’ Monster, which collectively form a group known as Luolishaniidae. Fossils of these creatures are hard to come by and mostly fragmentary, so the discovery of Collinsium greatly improves our understanding of these bizarre organisms.”
The fossil was found in the Xiaoshiba deposit in southern China, a site which is less-explored than the larger Chengjiang deposit nearby, but has turned up fascinating and well-preserved specimens from this key period in Earth’s history.
“Animals during the Cambrian were incredibly diverse, with lots of interesting behaviours and modes of living,” said Ortega-Hernández. “The Chinese Collins’ Monster was one of these evolutionary ‘experiments’ – one which ultimately failed as they have no living direct ancestors – but it’s amazing to see how specialised many animals were hundreds of millions of years ago. At its core, the study of the fossil record seeks answers about the evolution of life on Earth that can only be found in deep time. All the major biological events responsible for shaping the world we inhabit, such as the origin of life, the early diversification of animals, or the establishment of the modern biosphere, are intimately linked to the complex geological history of our planet.”
The research was funded by the National Natural Science Foundation of China, Emmanuel College, Cambridge, and the Templeton World Charity Foundation. 

- See more at: http://www.cam.ac.uk/research/news/spiky-monsters-new-species-of-super-armoured-worm-discovered#sthash.8IxqS2fW.dpuf

Spiky monsters: new species of ‘super-armoured’ worm discovered

• Research
• News

• Spiky monsters: new species of ‘super-armoured’ worm discovered

A newly-identified species of spike-covered worm with legs, which lived 500 million years ago, was one of the first animals on Earth to develop armour for protection.

Collins’ Monster sort of looks like Hallucigenia on steroids

Javier Ortega-Hernández

A new species of ‘super-armoured’ worm, a bizarre, spike-covered creature which ate by filtering nutrients out of seawater with its feather-like front legs, has been identified by palaeontologists. The creature, which lived about half a billion years ago, was one of the first animals on Earth to develop armour to protect itself from predators and to use such a specialised mode of feeding.
The creature, belonging to a poorly understood group of early animals, is also a prime example of the broad variety of form and function seen in the early evolutionary history of a modern group of animals that, today, are rather homogenous. The results, from researchers at the University of Cambridge and Yunnan University in China, are published today (29 June) in the journal PNAS.
The creature has been named Collinsium ciliosum, or Hairy Collins’ Monster, named for the palaeontologist Desmond Collins, who discovered and first illustrated a similar Canadian fossil in the 1980s. The newly-identified species lived in what is now China during the Cambrian explosion, a period of rapid evolutionary development around half a billion years ago, when most major animal groups first appear in the fossil record.
A detailed analysis of its form and evolutionary relationships indicates that the Chinese Collins’ Monster is a distant early ancestor of modern velvet worms, or onychophorans, a small group of squishy animals resembling legged worms that live primarily in tropical forests around the world.
“Modern velvet worms are all pretty similar in terms of their general body organisation and not that exciting in terms of their lifestyle,” said Dr Javier Ortega-Hernández of Cambridge’s Department of Earth Sciences, one of the paper’s lead authors. “But during the Cambrian, the distant relatives of velvet worms were stunningly diverse and came in a surprising variety of bizarre shapes and sizes.”
The pattern of diverse ancestors leading to relatively unvaried modern relatives has been observed in other groups in the fossil record, including sea lilies (crinoids) and lamp shells (brachiopods). However, this is the first time that this evolutionary pattern has been observed in a mostly soft-bodied group.
Ortega-Hernández and his colleagues identified a remarkably well-preserved fossil from southern China, which included details of the full body organisation, the digestive tract, even down to a delicate coat of hair-like structures on the front end. Their analysis found it to be a new species – an eccentric ancestor of an otherwise straight-laced group.
The Chinese Collins’ Monster had a soft and squishy body, six pairs of feather-like front legs, and nine pairs of rear legs ending in claws. Since the clawed rear legs were not well-suited for walking along the muddy ocean floor, it is likely that Collinsium eked out an existence by clinging onto sponges or other hard substances by its back claws, while sieving out its food with its feathery front legs. Some modern animals, including bamboo shrimp, feed in a similar way, capturing passing nutrients with their fan-like forearms.
Given its sedentary lifestyle and soft body, the Chinese Collins’ Monster would have been a sitting duck for any predators, so it developed an impressive defence mechanism: as many as 72 sharp and pointy spikes of various sizes covering its body, making it one of the earliest soft-bodied animals to develop armour for protection.
The Chinese Collins’ Monster resembles Hallucigenia, another otherworldly Cambrian fossil, albeit one which has been the subject of much more study.
“Both creatures are lobopodians, or legged worms, but the Collins’ Monster sort of looks like Hallucigenia on steroids,” said Ortega-Hernández. “It had much heavier armour protecting its body, with up to five pointy spines per pair of legs, as opposed to Hallucigenia’s two. Unlike Hallucigenia, the limbs at the front of Collins’ Monster’s body were also covered with fine brushes or bristles that were used for a specialised type of feeding from the water column.”
The spines along Collinsium’s back had a cone-in-cone construction, similar to Russian nesting dolls. This same construction has also been observed in the closely-related Hallucigenia and the claws in the legs of velvet worms, making both Collinsium and Hallucigenia distant ancestors of modern onychophorans. According to Ortega-Hernández, “There are at least four more species with close family ties to the Collins’ Monster, which collectively form a group known as Luolishaniidae. Fossils of these creatures are hard to come by and mostly fragmentary, so the discovery of Collinsium greatly improves our understanding of these bizarre organisms.”
The fossil was found in the Xiaoshiba deposit in southern China, a site which is less-explored than the larger Chengjiang deposit nearby, but has turned up fascinating and well-preserved specimens from this key period in Earth’s history.
“Animals during the Cambrian were incredibly diverse, with lots of interesting behaviours and modes of living,” said Ortega-Hernández. “The Chinese Collins’ Monster was one of these evolutionary ‘experiments’ – one which ultimately failed as they have no living direct ancestors – but it’s amazing to see how specialised many animals were hundreds of millions of years ago. At its core, the study of the fossil record seeks answers about the evolution of life on Earth that can only be found in deep time. All the major biological events responsible for shaping the world we inhabit, such as the origin of life, the early diversification of animals, or the establishment of the modern biosphere, are intimately linked to the complex geological history of our planet.”
The research was funded by the National Natural Science Foundation of China, Emmanuel College, Cambridge, and the Templeton World Charity Foundation. 

- See more at: http://www.cam.ac.uk/research/news/spiky-monsters-new-species-of-super-armoured-worm-discovered#sthash.8IxqS2fW.dpuf

Spiky monsters: new species of ‘super-armoured’ worm discovered

• Research
• News

• Spiky monsters: new species of ‘super-armoured’ worm discovered

A newly-identified species of spike-covered worm with legs, which lived 500 million years ago, was one of the first animals on Earth to develop armour for protection.

Collins’ Monster sort of looks like Hallucigenia on steroids

Javier Ortega-Hernández

A new species of ‘super-armoured’ worm, a bizarre, spike-covered creature which ate by filtering nutrients out of seawater with its feather-like front legs, has been identified by palaeontologists. The creature, which lived about half a billion years ago, was one of the first animals on Earth to develop armour to protect itself from predators and to use such a specialised mode of feeding.
The creature, belonging to a poorly understood group of early animals, is also a prime example of the broad variety of form and function seen in the early evolutionary history of a modern group of animals that, today, are rather homogenous. The results, from researchers at the University of Cambridge and Yunnan University in China, are published today (29 June) in the journal PNAS.
The creature has been named Collinsium ciliosum, or Hairy Collins’ Monster, named for the palaeontologist Desmond Collins, who discovered and first illustrated a similar Canadian fossil in the 1980s. The newly-identified species lived in what is now China during the Cambrian explosion, a period of rapid evolutionary development around half a billion years ago, when most major animal groups first appear in the fossil record.
A detailed analysis of its form and evolutionary relationships indicates that the Chinese Collins’ Monster is a distant early ancestor of modern velvet worms, or onychophorans, a small group of squishy animals resembling legged worms that live primarily in tropical forests around the world.
“Modern velvet worms are all pretty similar in terms of their general body organisation and not that exciting in terms of their lifestyle,” said Dr Javier Ortega-Hernández of Cambridge’s Department of Earth Sciences, one of the paper’s lead authors. “But during the Cambrian, the distant relatives of velvet worms were stunningly diverse and came in a surprising variety of bizarre shapes and sizes.”
The pattern of diverse ancestors leading to relatively unvaried modern relatives has been observed in other groups in the fossil record, including sea lilies (crinoids) and lamp shells (brachiopods). However, this is the first time that this evolutionary pattern has been observed in a mostly soft-bodied group.
Ortega-Hernández and his colleagues identified a remarkably well-preserved fossil from southern China, which included details of the full body organisation, the digestive tract, even down to a delicate coat of hair-like structures on the front end. Their analysis found it to be a new species – an eccentric ancestor of an otherwise straight-laced group.
The Chinese Collins’ Monster had a soft and squishy body, six pairs of feather-like front legs, and nine pairs of rear legs ending in claws. Since the clawed rear legs were not well-suited for walking along the muddy ocean floor, it is likely that Collinsium eked out an existence by clinging onto sponges or other hard substances by its back claws, while sieving out its food with its feathery front legs. Some modern animals, including bamboo shrimp, feed in a similar way, capturing passing nutrients with their fan-like forearms.
Given its sedentary lifestyle and soft body, the Chinese Collins’ Monster would have been a sitting duck for any predators, so it developed an impressive defence mechanism: as many as 72 sharp and pointy spikes of various sizes covering its body, making it one of the earliest soft-bodied animals to develop armour for protection.
The Chinese Collins’ Monster resembles Hallucigenia, another otherworldly Cambrian fossil, albeit one which has been the subject of much more study.
“Both creatures are lobopodians, or legged worms, but the Collins’ Monster sort of looks like Hallucigenia on steroids,” said Ortega-Hernández. “It had much heavier armour protecting its body, with up to five pointy spines per pair of legs, as opposed to Hallucigenia’s two. Unlike Hallucigenia, the limbs at the front of Collins’ Monster’s body were also covered with fine brushes or bristles that were used for a specialised type of feeding from the water column.”
The spines along Collinsium’s back had a cone-in-cone construction, similar to Russian nesting dolls. This same construction has also been observed in the closely-related Hallucigenia and the claws in the legs of velvet worms, making both Collinsium and Hallucigenia distant ancestors of modern onychophorans. According to Ortega-Hernández, “There are at least four more species with close family ties to the Collins’ Monster, which collectively form a group known as Luolishaniidae. Fossils of these creatures are hard to come by and mostly fragmentary, so the discovery of Collinsium greatly improves our understanding of these bizarre organisms.”
The fossil was found in the Xiaoshiba deposit in southern China, a site which is less-explored than the larger Chengjiang deposit nearby, but has turned up fascinating and well-preserved specimens from this key period in Earth’s history.
“Animals during the Cambrian were incredibly diverse, with lots of interesting behaviours and modes of living,” said Ortega-Hernández. “The Chinese Collins’ Monster was one of these evolutionary ‘experiments’ – one which ultimately failed as they have no living direct ancestors – but it’s amazing to see how specialised many animals were hundreds of millions of years ago. At its core, the study of the fossil record seeks answers about the evolution of life on Earth that can only be found in deep time. All the major biological events responsible for shaping the world we inhabit, such as the origin of life, the early diversification of animals, or the establishment of the modern biosphere, are intimately linked to the complex geological history of our planet.”
The research was funded by the National Natural Science Foundation of China, Emmanuel College, Cambridge, and the Templeton World Charity Foundation. 

- See more at: http://www.cam.ac.uk/research/news/spiky-monsters-new-species-of-super-armoured-worm-discovered#sthash.8IxqS2fW.dpuf

Spiky monsters: new species of ‘super-armoured’ worm discovered

• Research
• News

• Spiky monsters: new species of ‘super-armoured’ worm discovered

A newly-identified species of spike-covered worm with legs, which lived 500 million years ago, was one of the first animals on Earth to develop armour for protection.

Collins’ Monster sort of looks like Hallucigenia on steroids

Javier Ortega-Hernández

A new species of ‘super-armoured’ worm, a bizarre, spike-covered creature which ate by filtering nutrients out of seawater with its feather-like front legs, has been identified by palaeontologists. The creature, which lived about half a billion years ago, was one of the first animals on Earth to develop armour to protect itself from predators and to use such a specialised mode of feeding.
The creature, belonging to a poorly understood group of early animals, is also a prime example of the broad variety of form and function seen in the early evolutionary history of a modern group of animals that, today, are rather homogenous. The results, from researchers at the University of Cambridge and Yunnan University in China, are published today (29 June) in the journal PNAS.
The creature has been named Collinsium ciliosum, or Hairy Collins’ Monster, named for the palaeontologist Desmond Collins, who discovered and first illustrated a similar Canadian fossil in the 1980s. The newly-identified species lived in what is now China during the Cambrian explosion, a period of rapid evolutionary development around half a billion years ago, when most major animal groups first appear in the fossil record.
A detailed analysis of its form and evolutionary relationships indicates that the Chinese Collins’ Monster is a distant early ancestor of modern velvet worms, or onychophorans, a small group of squishy animals resembling legged worms that live primarily in tropical forests around the world.
“Modern velvet worms are all pretty similar in terms of their general body organisation and not that exciting in terms of their lifestyle,” said Dr Javier Ortega-Hernández of Cambridge’s Department of Earth Sciences, one of the paper’s lead authors. “But during the Cambrian, the distant relatives of velvet worms were stunningly diverse and came in a surprising variety of bizarre shapes and sizes.”
The pattern of diverse ancestors leading to relatively unvaried modern relatives has been observed in other groups in the fossil record, including sea lilies (crinoids) and lamp shells (brachiopods). However, this is the first time that this evolutionary pattern has been observed in a mostly soft-bodied group.
Ortega-Hernández and his colleagues identified a remarkably well-preserved fossil from southern China, which included details of the full body organisation, the digestive tract, even down to a delicate coat of hair-like structures on the front end. Their analysis found it to be a new species – an eccentric ancestor of an otherwise straight-laced group.
The Chinese Collins’ Monster had a soft and squishy body, six pairs of feather-like front legs, and nine pairs of rear legs ending in claws. Since the clawed rear legs were not well-suited for walking along the muddy ocean floor, it is likely that Collinsium eked out an existence by clinging onto sponges or other hard substances by its back claws, while sieving out its food with its feathery front legs. Some modern animals, including bamboo shrimp, feed in a similar way, capturing passing nutrients with their fan-like forearms.
Given its sedentary lifestyle and soft body, the Chinese Collins’ Monster would have been a sitting duck for any predators, so it developed an impressive defence mechanism: as many as 72 sharp and pointy spikes of various sizes covering its body, making it one of the earliest soft-bodied animals to develop armour for protection.
The Chinese Collins’ Monster resembles Hallucigenia, another otherworldly Cambrian fossil, albeit one which has been the subject of much more study.
“Both creatures are lobopodians, or legged worms, but the Collins’ Monster sort of looks like Hallucigenia on steroids,” said Ortega-Hernández. “It had much heavier armour protecting its body, with up to five pointy spines per pair of legs, as opposed to Hallucigenia’s two. Unlike Hallucigenia, the limbs at the front of Collins’ Monster’s body were also covered with fine brushes or bristles that were used for a specialised type of feeding from the water column.”
The spines along Collinsium’s back had a cone-in-cone construction, similar to Russian nesting dolls. This same construction has also been observed in the closely-related Hallucigenia and the claws in the legs of velvet worms, making both Collinsium and Hallucigenia distant ancestors of modern onychophorans. According to Ortega-Hernández, “There are at least four more species with close family ties to the Collins’ Monster, which collectively form a group known as Luolishaniidae. Fossils of these creatures are hard to come by and mostly fragmentary, so the discovery of Collinsium greatly improves our understanding of these bizarre organisms.”
The fossil was found in the Xiaoshiba deposit in southern China, a site which is less-explored than the larger Chengjiang deposit nearby, but has turned up fascinating and well-preserved specimens from this key period in Earth’s history.
“Animals during the Cambrian were incredibly diverse, with lots of interesting behaviours and modes of living,” said Ortega-Hernández. “The Chinese Collins’ Monster was one of these evolutionary ‘experiments’ – one which ultimately failed as they have no living direct ancestors – but it’s amazing to see how specialised many animals were hundreds of millions of years ago. At its core, the study of the fossil record seeks answers about the evolution of life on Earth that can only be found in deep time. All the major biological events responsible for shaping the world we inhabit, such as the origin of life, the early diversification of animals, or the establishment of the modern biosphere, are intimately linked to the complex geological history of our planet.”
The research was funded by the National Natural Science Foundation of China, Emmanuel College, Cambridge, and the Templeton World Charity Foundation. 

- See more at: http://www.cam.ac.uk/research/news/spiky-monsters-new-species-of-super-armoured-worm-discovered#sthash.8IxqS2fW.dpuf