Jaws made of bone are commonplace in the animal kingdom. However, how jaws developed in the course of evolution is still a mystery. Under the direction of paleontologist Nicolas Goudemand, a team of researchers from the University of Zurich and the European Synchrotron Radiation Facility set about solving this puzzle. Living and extinct jawless animals can yield clues as to the development of the jaw.
The researchers studied fossilized conodonts – extinct, eel-shaped animals whose precise relationship with the actual vertebrates is still a matter of debate. For their project, which was funded by the Swiss National Science Foundation and just published in the American journal PNAS, the researchers analyzed new conodont fossils that date from around the biggest mass extinction event at the boundary between the Permian and Triassic periods.
Multitasking thanks to teeth on upper lips and tongue
In some of these new fossils discovered in China, the researchers noticed several conjoined tooth-like structures that occupied an unusual position in the mouth. Based on this discovery and the re-evaluation of other unusually constructed conodont feeding apparatus, the scientists developed a 3D animated model that shows how conodonts fed: most conodonts had to have two upper lips, upon each of which there was a long, fang-like structure. The conodonts also had a kind of tongue bearing a complex set of spiny or comb-like ‘teeth’. The ‘tongue’ rested on pulley-like cartilage and could be moved backwards and forwards thanks to two opposing muscles. The conodonts used the ‘tongue’ and lips to grab food before two pairs of relatively robust, sometimes molar-like ‘throat teeth’ ground and cut it up.
Similarity with lampreys
The conodonts’ unique feeding mechanism is fairly similar to that of the extant lamprey, which is widely regarded as the extinct conodonts’ nearest relative. The new findings confirm that conodonts are to be considered primitive vertebrates from an evolutionary point of view. Moreover, due to the comparative feeding mechanism and other similarities, lampreys and conodonts must have a common ancestor which was one of the first vertebrates. This common ancestor must also have had a tongue mounted on pulley-like cartilage and therefore eaten in the same manner as the conodonts.
Nicolas Goudemand, Michael J. Orchard, Séverine Urdy, Hugo Bucher, Paul Tafforeau: Synchrotron-aided reconstruction of the conodont feeding apparatus and implications for the mouth of the first vertebrates, PNAS early edition, doi 10.1073/pnas.1101754108Contact
Beat Müller | idw
Symbiotic bacteria: from hitchhiker to beetle bodyguard
28.04.2017 | Johannes Gutenberg-Universität Mainz
Nose2Brain – Better Therapy for Multiple Sclerosis
28.04.2017 | Fraunhofer-Institut für Grenzflächen- und Bioverfahrenstechnik IGB
More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.
Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...
Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.
"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...
The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.
Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...
The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...
Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.
Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...
28.04.2017 | Event News
20.04.2017 | Event News
18.04.2017 | Event News
28.04.2017 | Medical Engineering
28.04.2017 | Earth Sciences
28.04.2017 | Life Sciences