Exceptional fossil fish reveals new evolutionary mechanism for body elongation
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."
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.
Source: University of Zurich
- Exceptional fossil fish reveals new evolutionary mechanism for body elongationfrom Science DailyMon, 7 Oct 2013, 10:00:22 EDT
- Fish Fossil Shows New Evolutionary Mechanismfrom Science BlogMon, 7 Oct 2013, 9:30:25 EDT
- Exceptional fossil fish reveals new evolutionary mechanism for body elongationfrom PhysorgMon, 7 Oct 2013, 6:00:28 EDT
Latest Science NewsletterGet the latest and most popular science news articles of the week in your Inbox! It's free!
Check out our next project, Biology.Net
From other science news sites
Popular science news articles
- The Lancet Psychiatry: Depression symptoms that steadily increase in later life predict higher dementia risk, study shows
- UNC-Chapel Hill scientists find likely cause for recent southeast US earthquakes
- Introducing the disposable laser
- Scientists challenge conventional wisdom to improve predictions of bootstrap current
- Children with ADHD may benefit from following healthy behaviors, new study suggests
- New tech uses hardware, software to train dogs more efficiently
- New interpretation of the Rök runestone inscription changes view of Viking Age
- Hydropeaking of river water levels is disrupting insect survival, river ecosystems
- River food webs threatened by widespread hydropower practice
- Reef system with 10,000 km2 found at the Amazon River mouth
- Bird genomes contain 'fossils' of parasites that now infect humans
- Dartmouth-led study of chimpanzees explores the early origins of human hand dexterity
- Fructose alters hundreds of brain genes, which can lead to a wide range of diseases
- Study finds explanation for some treatment-resistant breast cancers
- Researchers identify new mechanism to target 'undruggable' cancer gene