Mollusk fossils push back evolution, ROM scientists say

Life 560 million years ago more advanced than previously believed, article says.

Two Canadian paleontologists have discovered dozens of fossils of a soft-bodied, deep-sea dweller that lived more than half a billion years ago, adding one more piece to the enigmatic puzzle that is the history of life on Earth.

The 189 well-preserved fossil specimens of Odontogriphus omalus have been interpreted as the world's oldest known soft-bodied mollusk, and were found in British Columbia's mountains in the Burgess Shale, one of the most important fossil sites in the world.

The newly discovered fossils are remarkable, one of the researchers notes, because there are perfect impressions of all of the animal's soft tissues.

The fossils show the early mollusk had an oval body ranging in size from a few millimetres to 20 centimetres with simple gill-like structures surrounding a muscular sole or "foot" on the underside.

This discovery pushes back the history of animal evolution tens of millions of years to 560 million years ago in Precambrian time (543 million years ago and earlier), according to the Royal Ontario Museum's David Rudkin, co-author of the article published in today's issue of the journal Nature.

Very few fossil specimens have been found from that time period. The Cambrian Period (543 million to 490 million years ago) marked the sudden appearance of complex multicellular macroscopic organisms.

In the Precambrian era, before the so-called explosion, organisms were thought to be much simpler, but this study shows that was not the case.

"This is a crucial interval in evolutionary history because it seems to represent a time in which a great deal happened," he said.

"Odontogriphus seems to be a late holdover that somehow got preserved in with the creatures from the Cambrian . . . opening up new windows on evolution for us," Mr. Rudkin said.

The specimens were collected over 15 years in the late 1980s and 1990s by the ROM and, upon closer examination, were found to have distinguishing "molluskan" features including a specialized feeding structure called a radula, made up of short rows of small, tooth-like elements that would wave and sweep food into the mouth.

Odontogriphus, which translates to "toothed riddle" was originally discovered in 1976 from a single, poorly preserved specimen. Until now, it has been described as an "enigmatic organism," according to the study's lead author, Jean-Bernard Caron, also of the ROM.

"Our study redescribes and reinterprets previously unrecognized features that link Odontogriphus to the mollusks, one of the most diverse and important groups of animals living today," Dr. Caron said.

Odontogriphus predates modern-day mollusks -- with 200,000 living species today including snails, clams, squids and octopuses -- which began to develop hard shells during the Cambrian Period to survive.

"They were the last of their kind and they were dying out because the sea floor was changing and all these other animals started developing hard parts and new strategies for dealing with predators," Mr. Rudkin said. "The successful mollusks are those that branched off and developed shells."

Mr. Rudkin said the fact that many mollusks have survived such a catastrophic extinction could shed light on the evolutionary path many animals may take.

"Those lessons we learn from the past -- about where groups of organisms originated, when they become extinct, how they became extinct, or if they didn't become extinct entirely, how they recovered from extinction -- we use that kind of historical background to help us predict what might happen in modern extinction circumstances. Maybe there's a lesson in there for us."

Life 560 million years ago more advanced than previously believed, article says.

The specimens were collected over 15 years in the late 1980s and 1990s by the ROM

Seems as if we have some "dating" questions.

Not quite so old dates in 2004

Only one other organism - living or fossil - has a body design and feeding apparatus like that of Bowengriphus. The other 'Blob' is named Odontogriphus omalus. It was described in 1976 from much older (Middle Cambrian, 515 million year old) rocks inCanada. Odontogriphus and Bowengriphus are separated from each other by some 265 million years and half a world geographically; Odontogriphus is marine, whereas Bowengriphus lived in fresh water. Still, the two share enough similarities to suggest that they are each others' closest known relative, and they are classified together in the extinct group Odontogriphidae. Their position in the animal kingdom remains an enigma.

You don't believe the date controversy? Well hot off the press from Nature. A soft-bodied mollusc with radula from the Middle Cambrian Burgess Shale

Nature 442, 159-163(13 July 2006) | doi:10.1038/nature04894; Received 15 February 2006; Accepted 8 May 2006

A soft-bodied mollusc with radula from the Middle Cambrian Burgess Shale

Jean-Bernard Caron¹, Amélie Scheltema², Christoffer Schander³ and David Rudkin¹

Odontogriphus omalus was originally described as a problematic non-biomineralized lophophorate organism. Here we re-interpret Odontogriphus based on 189 new specimens including numerous exceptionally well preserved individuals from the Burgess Shale collections of the Royal Ontario Museum. This additional material provides compelling evidence that the feeding apparatus in Odontogriphus is a radula of molluscan architecture comprising two primary bipartite tooth rows attached to a radular membrane and showing replacement by posterior addition. Further characters supporting molluscan affinity include a broad foot bordered by numerous ctenidia located in a mantle groove and a stiffened cuticular dorsum. Odontogriphus has a radula similar to Wiwaxia corrugata but lacks a scleritome. We interpret these animals to be members of an early stem-group mollusc lineage that probably originated in the Neoproterozoic Ediacaran Period, providing support for the retention of a biomat-based grazing community from the late Precambrian Period until at least the Middle Cambrian.

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Aha! The moving date is nothing but a speculation(notice in the title that the fossil comes from the Middle Cambrian), We interpret these animals to be members of an early stem-group mollusc lineage that probably originated in the Neoproterozoic Ediacaran Period.

http://creationsafaris.org/

Cambrian Mollusk: Does It Help Animal Evolution Story?

07/13/2006

A soft-bodied mollusk named Odontogriphus known from the Burgess Shale, placed in the Middle Cambrian, has been described in more detail in Nature.1 If the Middle Cambrian is well after the Cambrian explosion, how can the authors claim this pushes the story of animal evolution far back into the Precambrian, before the explosion? A reporter for the Globe and Mail learned this from David Rudkin, one of the four co-authors of the paper:

This discovery pushes back the history of animal evolution tens of millions of years to 560 million years ago in Precambrian time (543 million years ago and earlier), according to the Royal Ontario Museum’s David Rudkin, co-author of the article published in today’s issue of the journal Nature.

This interpretation is based on perceived similarities with Kimberella, an unusual flattened, frond-like fossil categorized as Ediacaran (see 08/19/2004), dated at 555 million years ago in the late Precambrian. Yet a look at the original paper shows that the association is tenuous: “Odontogriphus and perhaps the Ediacaran form Kimberella possess distinctive characters that place them in the molluscs before the acquisition of a calcified dorsum,” it says. It qualifies the association with prefaces like, “If the interpretation of Kimberella as an early mollusc-like organism with radula is correct,” and portrays affinities with other early and mid-Cambrian mollusk fossils as “ambiguous” and “highly contentious.”

A look at their timeline chart demonstrates the point. There are more dashed lines and question marks than solid lines. All the indisputable mollusk fossils are found in the early or mid Cambrian, side by side. The evolutionary relationships are inferred by dashed lines extending into the Precambrian, with no fossils except for the puzzling Kimberella, which may have nothing to do with mollusks.

Moreover, the Globe and Mail article admits that very few fossils exist from the Precambrian, and that the Cambrian “marked the sudden appearance of complex multicellular macroscopic organisms” (see 04/23/2006). It also states that “In the Precambrian era, before the so-called explosion, organisms were thought to be much simpler, but this study shows that was not the case.” The paper describes these organisms as possessing a nervous system, a digestive system, reproductive system, excretory system, salivary glands and neat rows of teeth (radula). Nor is Odontogriphus the new kid on the block. The authors describe it as a holdover from “a handful of Cambrian fossils that probably represent surviving Neoproterozoic lineages” that survived whatever made the Ediacaran biota go extinct.

Such statements would seem to pose severe challenges to evolutionary theory, yet the news report speaks glowingly of how this fossil is helping evolutionists rather than hurting their case. “This is a crucial interval in evolutionary history because it seems to represent a time in which a great deal happened,” Rudkin is quoted as saying. He added that the specimen is “opening up new windows on evolution for us.” The article ends with a call for us to learn the lessons of evolution:

Mr. Rudkin said the fact that many mollusks have survived such a catastrophic extinction could shed light on the evolutionary path many animals may take.

“Those lessons we learn from the past — about where groups of organisms originated, when they become extinct, how they became extinct, or if they didn’t become extinct entirely, how they recovered from extinction — we use that kind of historical background to help us predict what might happen in modern extinction circumstances. Maybe there’s a lesson in there for us.”

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1Caron et al., “A soft-bodied mollusc with radula from the Middle Cambrian Burgess Shale,” Nature 442, 159-163(13 July 2006) | doi:10.1038/nature04894; Received 15 February 2006; Accepted 8 May 2006.

The lesson is not to tell myths and call it science. This paper registered multiple hits on our Baloney Detector. Enough baloney, and you have a virtual big lie.

These extinct mollusks with all their complex parts have nothing to do with evolution. If this is a window on evolution, it’s a new view of the wreckage. How scientists can take evidence that falsifies their view and turn it into praise service for Charlie is another example of the shameful shenanigans of the shameless Darwin Party these days. Their shifty shell game is a sham and should be shot down by those who respect real science sans spin.

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A soft-bodied mollusc with radula from the Middle Cambrian Burgess Shale

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