(Press-News.org) Snake and eel bodies are elongated, slender and flexible in all three dimensions. This striking body plan has evolved many times independently in the more than 500 million years of vertebrate animals history. Based on the current state of knowledge, the extreme elongation of the body axis occurred in one of two ways: either through the elongation of the individual vertebrae of the vertebral column, which thus became longer, or through the development of additional vertebrae and associated muscle segments.
Long body thanks to doubling of the vertebral arches
A team of paleontologists from the University of Zurich headed by Professor Marcelo Sánchez-Villagra now reveal that a third, previously unknown mechanism of axial skeleton elongation characterized the early evolution of fishes, as shown by an exceptionally preserved form. Unlike other known fish with elongate bodies, the vertebral column of Saurichthys curionii does not have one vertebral arch per myomeric segment, but two, which is unique. This resulted in an elongation of the body and gave it an overall elongate appearance. "This evolutionary pattern for body elongation is new," explains Erin Maxwell, a postdoc from Sánchez-Villagra's group. "Previously, we only knew about an increase in the number of vertebrae and muscle segments or the elongation of the individual vertebrae."
VIDEO:
This video shows how the number of skeletal elements in the vertebral column became doubled in Saurichthys without an increase in the number of vertebrae.
Click here for more information.
The fossils studied come from the Monte San Giorgio find in Ticino, which was declared a world heritage site by UNESCO in 2003. The researchers owe their findings to the fortunate circumstance that not only skeletal parts but also the tendons and tendon attachments surrounding the muscles of the primitive predatory fish had survived intact. Due to the shape and arrangement of the preserved tendons, the scientists are also able to draw conclusions as to the flexibility and swimming ability of the fossilized fish genus. According to Maxwell, Saurichthys curionii was certainly not as flexible as today's eels and, unlike modern oceanic fishes such as tuna, was probably unable to swim for long distances at high speed. Based upon its appearance and lifestyle, the roughly half-meter-long fish is most comparable to the garfish or needlefish that exist today.
INFORMATION:
Literature:
Erin E. Maxwell, Heinz Furrer, Marcelo R. Sánchez-Villagra. Exceptional fossil preservation demonstrates a new mode of axial skeleton elongation in early ray-finned fishes. Nature Communications, October 7, 2013. Doi: 10.1038/ncomms3570
Contact:
Prof. Dr. Marcelo Sánchez-Villagra
Paläontologisches Institut und Museum
University of Zurich
Tel. +41 44 634 23 42 / 23 23
E-Mail: m.sanchez@pim.uzh.ch
Exceptional fossil fish reveals new evolutionary mechanism for body elongation
2013-10-07
ELSE PRESS RELEASES FROM THIS DATE:
Researchers highlight emerging applications of Bio-Rad's Droplet Digital™ PCR Technology at the 2013 Digital PCR Conference
2013-10-07
Hercules, CA — October 7, 2013 — Since its introduction in 2011, Bio-Rad Laboratory's Droplet Digital PCR (ddPCR™) technology has demonstrated the potential to be a transformative technology, particularly in clinical applications. At the second annual CHI Digital PCR Conference in San Diego, CA, Oct. 7–9, 2013, 12 scientists using Bio-Rad's Droplet Digital PCR systems will highlight ddPCR applications that have advanced their research. These researchers will share how ddPCR technology provides greater precision, reproducibility, and sensitivity than real-time PCR approaches ...
Food addiction a step closer to formal diagnostic status -- or not?
2013-10-07
BARCELONA, SPAIN (7 October 2013) – Food addiction is not yet recognised as a mental disorder but certain obese individuals clearly display addictive-like behaviour towards food. To achieve a formal diagnostic status, 'food addiction' requires a stronger evidence base to support the claim that certain ingredients have addictive properties identical to addictive drugs of abuse. This topic is up for debate in the session, 'Binge eating obesity is a food addiction'.
This year's fifth edition of the DSM (Diagnostic and Statistical Manual of Mental Disorders) recognises 'binge ...
NAC amino acid offers a potential therapeutic alternative in psychiatric disorders
2013-10-07
BARCELONA, SPAIN (7 October 2013) – Improved understanding of the roles of inflammation and oxidative stress in psychiatric disorders has generated new leads in the search for novel therapies. One such investigative compound currently in clinical trials is an amino acid, N-Acetyl Cysteine (NAC), which appears to reduce the core symptoms of bipolar disorder, schizophrenia, depression, autism and cravings in addictions including cocaine, cannabis abuse and cigarette smoking.
At the start of the decade of the brain, in the early 1990s, there was great hope that a flurry ...
Pre-menstrual dysphoric disorder helps elucidate role of female sex hormones on mood
2013-10-07
BARCELONA, SPAIN (7 October 2013) – Improved understanding of the role of female sex hormones on the drivers and symptoms of premenstrual dysphoric disorder (PMDD) may shed light on the complex interactions between sex hormones and mood, potentially helping to explain the increased prevalence of mood disorders in women.
Most women are unaffected by the hormonal changes of the menstrual cycle, however approximately 20% of women experience premenstrual syndrome (PMS), or premenstrual dysphoric disorder (PMDD), a more severe form of PMS. The latter affects roughly 5% of ...
GABA inverse agonist restores cognitive function in Down's syndrome
2013-10-07
BARCELONA, SPAIN (7 October 2013) – A selective GABA inverse agonist has restored cognitive function in a mouse model of Down's syndrome (DS) and has the potential to benefit humans, French researchers have revealed.
"The drug we used is a specific GABA-A α5 inverse agonist (α5IA) that hypothetically could combat the abnormal neuronal excitation/inhibition balance associated with DS", explained lead researcher Dr Benoit Delatour from the Research Centre of the Institute of Brain and Spinal Cord (Centre de Recherche de l'Institut du Cerveau et de Moelle Epinière) ...
Adult ADHD undertreated despite effective interventions
2013-10-07
BARCELONA, SPAIN (7 October 2013) – Up to two-thirds of children with attention deficit/hyperactivity disorder (ADHD) find their disorder persists into adulthood yet only a small proportion of adults ever receive a formal diagnosis and treatment, research suggests.
ADHD, a chronic neurodevelopmental disorder that begins in childhood, continues into adulthood in the majority of children. Prevalence figures show that 3-4% of adults are affected by ADHD and it is associated with a broad range of psychosocial impairments.
Dr Esther Sobanski investigates the pharmacological ...
Disney Research develops algorithm for rendering 3-D tactile features on touch surfaces
2013-10-07
A person sliding a finger across a topographic map displayed on a touch screen can feel the bumps and curves of hills and valleys, despite the screen's smooth surface, with the aid of a novel algorithm created by Disney Research, Pittsburgh for tactile rendering of 3D features and textures.
By altering the friction encountered as a person's fingertip glides across a surface, the Disney algorithm can create a perception of a 3D bump on a touch surface without having to physically move the surface. The method can be used to simulate the feel of a wide variety of objects ...
Disney Research discovers rubbing, tapping paper-like material creates electrical current
2013-10-07
Electric current sufficient to light a string of LEDs, activate an e-paper display or even trigger action by a computer can be generated by tapping or rubbing simple, flexible generators made of paper, thin sheets of plastic and other everyday materials, researchers at Disney Research, Pittsburgh, have demonstrated.
This new approach to energy harvesting uses electrets, materials with special electrical properties that already are used in microphones and in tiny MEMS devices. This latest application, developed by researchers at Disney Research, Pittsburgh and at Carnegie ...
Minute traits and DNA link grass species from Old and New Worlds
2013-10-07
The kinds of traits that show genealogical relationships between species are often minute and easily overlooked.
Dr. Neil Snow, a botanist at Pittsburg State University, published a paper in 1996 that included observations of some odd-shaped hairs on three species of grass native to Africa. Their odd shape stems from distinctly swollen tips that are then pinched into a small party-hat structure at the very apex.
"A tongue-twisting technical term for that shape is 'clavicorniculate', but 'club-shaped' is a workable simplification we often prefer," remarked Snow.
In ...
Dog's mood offers insight into owner's health
2013-10-07
Monitoring a dog's behaviour could be used as an early warning sign that an older owner is struggling to cope or their health is deteriorating.
Experts at Newcastle University, UK, are using movement sensors to track normal dog behaviour while the animals are both home alone and out-and-about.
Providing a unique insight into the secret life of man's best friend, the sensors show not only when the dog is on the move, but also how much he is barking, sitting, digging and other key canine behaviours.
By mapping the normal behaviour of a healthy, happy dog, Dr Cas Ladha, ...