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Teeth appeared earlier than expected, 410 mya


Romundina fossil/Martin Rücklin, Naturalis Biodiversity Center
Jaws were also more complex than expected.

From ScienceDaily:

A tiny tooth plate of the 410 million year old fossil fish Romundina stellina indicates that teeth evolved earlier in the tree of life than recently thought.

That is a while back.

The tooth plate of just some millimeters in size had been in a box for more than 40 years, without being recognized after the discovery and preparation of the fish it belonged to.

Because no one expected to find anything like that. And few had any special desire to

Everyone knows evolution is a long, slow process of natural selection acting on random mutation (Darwinian evolution). Every third rate biology teacher teaches that, and so do first raters, because they don’t dare teach anything else, even though they would have to know better by now.

Philip Donoghue from the University of Bristol in the UK explains: “We show that the earliest teeth were like our own — but also structured like body scales in primitive fishes. This supports the view that teeth evolved from scales, which arose much earlier in vertebrate evolution.”

Rücklin adds: “Our results suggest that teeth originated deeper in the tree of life than we thought. We will have to look into more basal jawed vertebrates and also jawless fossils. Earliest jaws and teeth seem to be less integrated than we thought and teeth look more complex than expected. I am very happy that my research and our collaboration will be supported by the Vidi-grant of the Netherlands Organization for Scientific Research (NWO) in the next five years, enabling us to investigate these early stages of teeth and how the complex system of our own jaws and teeth evolved.” More.

The basic problem this earlier than thought/more complex than thought stuff represents for Darwinian evolution is that it continually diminishes the time frame within which things could somehow just happen by chance. So it is better to just report the facts and flee the scene.

Here’s the abstract:

Theories on the origin of vertebrate teeth have long focused on chondrichthyans as reflecting a primitive condition—but this is better informed by the extinct placoderms, which constitute a sister clade or grade to the living gnathostomes. Here, we show that ‘supragnathal’ toothplates from the acanthothoracid placoderm Romundina stellina comprise multi-cuspid teeth, each composed of an enameloid cap and core of dentine. These were added sequentially, approximately circumferentially, about a pioneer tooth. Teeth are bound to a bony plate that grew with the addition of marginal teeth. Homologous toothplates in arthrodire placoderms exhibit a more ordered arrangement of teeth that lack enameloid, but their organization into a gnathal, bound by layers of cellular bone associated with the addition of each successional tooth, is the same. The presence of enameloid in the teeth of Romundina suggests that it has been lost in other placoderms. Its covariation in the teeth and dermal skeleton of placoderms suggests a lack of independence early in the evolution of jawed vertebrates. It also appears that the dentition—manifest as discrete gnathal ossifications—was developmentally discrete from the jaws during this formative episode of vertebrate evolution. (Public access) – M. Rucklin, P. C. J. Donoghue. Romundina and the evolutionary origin of teeth. Biology Letters, 2015; 11 (6): 20150326 DOI: 10.1098/rsbl.2015.0326

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"This supports the view that teeth evolved from scales" Oh, that explains it. I was thinking maybe maybe teeth evolved from fur? No, fur evolved from skin that evolved from scales. Scales are neat. Evolution is cool. Evolution explains. ppolish
Of all the 'earlier than expected' findings that have been referenced on UD, I have to say that the following are my favorites: Half-Billion-Year-Old Heart Found More Complex than Today’s - April 24, 2014 Excerpt: "520 million years ago, the first known animal heart was formed. It was the heart of an ancient shrimp, and quite a heart it was. For it, and its vascular system, have been found to be more complex than that of modern shrimp," http://www.biosciencetechnology.com/articles/2014/04/half-billion-year-old-heart-found-more-complex-today%E2%80%99s?et_cid=3902736&et_rid=653535995&type=cta Complex Arthropod Eyes Found in Early Cambrian - June 2011 Excerpt: Complex eyes with modern optics from an unknown arthropod, more complex than trilobite eyes, have been discovered in early Cambrian strata from southern Australia.,,, Here we report exceptionally preserved fossil eyes from the Early Cambrian (~515 million years ago) Emu Bay Shale of South Australia, revealing that some of the earliest arthropods possessed highly advanced compound eyes, each with over 3,000 large ommatidial lenses and a specialized ‘bright zone’. These are the oldest non-biomineralized eyes known in such detail, with preservation quality exceeding that found in the Burgess Shale and Chengjiang deposits. Non-biomineralized eyes of similar complexity are otherwise unknown until about 85 million years later. The arrangement and size of the lenses indicate that these eyes belonged to an active predator that was capable of seeing in low light. The eyes are more complex than those known from contemporaneous trilobites and are as advanced as those of many living forms. They provide further evidence that the Cambrian explosion involved rapid innovation in fine-scale anatomy as well as gross morphology, http://crev.info/content/110629-complex_arthropod_eyes_found_in_early_cambrian 500 million-year-old super predator had remarkable vision - Dec 07, 2011 Excerpt: The fossils represent compound eyes - the multi-faceted variety seen in arthropods such as flies, crabs and kin - and are amongst the largest to have ever existed, with each eye up to 3 cm in length and containing over 16,000 lenses. The number of lenses and other aspects of their optical design suggest that Anomalocaris would have seen its world with exceptional clarity whilst hunting in well-lit waters. Only a few arthropods, such as modern predatory dragonflies, have similar resolution. http://www.physorg.com/news/2011-12-million-year-old-super-predator-remarkable-vision.html Anomalocaris (had teeth of some sort!) – Sea Monster – video http://www.youtube.com/watch?&v=ice47loNmsc bornagain77
ok, but what were they for? Mung

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