Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Armour-plated fish and the evolution of dentists

08.01.2002


The discovery of small spikes lining the mouths of primitive fossil fish reveal surprising new details about how early animals fed. New research published today in a Royal Society paper sheds light on how teeth evolved.



Primitive fish did not have jaws or fins but were covered in rigid bony scales and resembled small armour-plated submarines. Dr Mark Purnell, a palaeontologist at the University of Leicester, has discovered that heterostracans, one of the most important groups of these early fish, had small spiky structures lining the inside edge of the mouth. These structures were made of hard dentine and were possibly the precursors of teeth as we know them today.

Only animals with backbones have true teeth, and the enamel and dentine of which they are made are the hardest materials in the body. ‘If you go looking for fossils of sharks, dinosaurs or any other vertebrate animal, you are more likely to find teeth than bones. Yet, surprisingly, mystery and uncertainty still surround the questions of when teeth first evolved and what they were used for,’ says Dr Purnell.


These new discoveries indicate that these early ‘teeth’ were not separated, individual structures but were modified from the armour plating that shielded the outside of the body. They had sharp points, cusps and ridges, but, unlike teeth, these points all faced forwards, and the fish could not have bitten or grabbed their food, or consumed anything but very small or soft items. This new evidence suggests that these early ‘teeth’ evolved not in a ferocious biting creature, but from the bony scales of a slime-slurping sucker.

Understanding how, when, and why animals first cut their teeth more than 400 million years ago is fundamental to understanding why the world around us is as it is. ‘Imagine a world without teeth – the history of life would certainly have taken a different course. Sharks would no longer be terrifying and dentists, more frightening to many people, would never have evolved,’ adds Dr Purnell.

Dr Mark Purnell | alphagalileo

More articles from Life Sciences:

nachricht Rainbow colors reveal cell history: Uncovering β-cell heterogeneity
22.09.2017 | DFG-Forschungszentrum für Regenerative Therapien TU Dresden

nachricht The pyrenoid is a carbon-fixing liquid droplet
22.09.2017 | Max-Planck-Institut für Biochemie

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: The pyrenoid is a carbon-fixing liquid droplet

Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.

A warming planet

Im Focus: Highly precise wiring in the Cerebral Cortex

Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.

The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

Im Focus: Ultrafast snapshots of relaxing electrons in solids

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...

Im Focus: Quantum Sensors Decipher Magnetic Ordering in a New Semiconducting Material

For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.

Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Rainbow colors reveal cell history: Uncovering β-cell heterogeneity

22.09.2017 | Life Sciences

Penn first in world to treat patient with new radiation technology

22.09.2017 | Medical Engineering

Calculating quietness

22.09.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>