Fish fossil unfolds clues to vertebrate brain evolution (2024)

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Fish fossil unfolds clues to vertebrate brain evolution? ›

A 319-million-year-old fossil provides the oldest known evidence of preserved vertebrate brain tissue. This specimen offers insights into the brain evolution of ray-finned fishes, the most diverse group of living vertebrates.

In the Ordovician Period around 480 million years ago, the spinal column began to take on its modern form and the first true fish appeared in the fossil record. Armored plates begin to develop on the head and thorax of fish. Astraspis was a jawless fish covered with star shaped scales from this time.

The preserved brain was found in a 319-million-year-old skull of an ancient fish called Coccocephalus wildi (C. wildi). The fossil was found in a British coal mine over a century ago. But it appeared to offer no valuable information and was soon donated to the Manchester Museum in England.

The CT-scanned skull of a 319-million-year-old fossilized fish, pulled from a coal mine in England more than a century ago, has revealed the oldest example of a well-preserved vertebrate brain. The brain and its cranial nerves are roughly an inch long and belong to an extinct bluegill-size fish.

There is nothing new about humans and all other vertebrates having evolved from fish. The conventional understanding has been that certain fish shimmied landwards roughly 370 million years ago as primitive, lizard-like animals known as tetrapods.

Using recovered fossils, paleontologists have reconstructed examples of radical evolutionary transitions in form and function. For example, the lower jaw of reptiles contains several bones, but that of mammals only one. The other bones in the reptile jaw unmistakably evolved into bones now found in the mammalian ear.

The early human embryo looks very similar to the embryo of any other mammal, bird or amphibian - all of which have evolved from fish. Your eyes start out on the sides of your head, but then move to the middle. The top lip along with the jaw and palate started life as gill-like structures on your neck.

(c) Vertebrate brains. Hint: Convergent evolution refers to the same function and different origin of unrelated organisms. They have analogous organs and they adapted to the same habitat. In convergent evolution species do not have a common ancestor.

For example, the brains of vertebrates acquired their basic forms such as the forebrain (telencephalon and diencephalon), midbrain, and hindbrain in the early stage of evolution, and have changed the morphology and function of each region while maintaining the basic structures during evolution.

The brain's structure is the outcome of an evolutionary process. The human brain has undergone an evolutionary process that began some 500 million years ago in the marine animals that lived submerged in the sand and which led to its first central nervous system building plan.

What was the first vertebrate found in evolution? ›

First vertebrates

Vertebrates originated during the Cambrian explosion, which saw a rise in organism diversity. The earliest known vertebrates belongs to the Chengjiang biota and lived about 518 million years ago. These include Haikouichthys, Myllokunmingia, Zhongjianichthys, and probably Haikouella.

The earliest vertebrates resembled hagfish and lived more than 500 million years ago. As other classes of fish appeared, they evolved traits such as a complete vertebral column, jaws, and a bony endoskeleton. Amphibians were the first tetrapod vertebrates a s well as the first vertebrates to live on land.

Paleontologist Matt Friedman was surprised to discover a remarkably detailed 319-million-year-old fish brain fossil while testing out micro-CT scans for a broader project.

The jaws were used in the buccal pump (observable in modern fish and amphibians) that pumps water across the gills of fish or air into the lungs in the case of amphibians. Over evolutionary time the more familiar use of jaws (to humans) in feeding was selected for and became a very important function in vertebrates.

About 99.8 percent of the vertebrates on the earth, including human beings, have jaws, which are collectively referred to as jawed vertebrates or jawed.

Fish began to evolve during the Cambrian explosion approximately 530 million years ago. The early chordates formed the skull and spinal column at this epoch, giving rise to the earliest craniates and vertebrates. The Agnatha, or jawless fish, are the earliest fish lineages.

The earliest fish, resembling living hagfish, evolved about 550 million years ago. Adaptations that eventually evolved in fish include a complete vertebral column, jaws, and an endoskeleton made of bones instead of cartilage. Fish live throughout the ocean and in freshwater lakes and streams.

530 million years ago: The Pikaia species, the first known fish on Earth, evolved in the middle of the Ordovician period. Around 530 million years ago: Haikouichthys, the earliest fish species discovered, evolved as one of the earliest vertebrate organisms in the world.

Underwater fossils are typically formed when sea organisms fall to the ocean floor and are covered in mud deposits. Over time, these build up to form limestone.

Several hundred million years ago, fish began to grow limbs that enabled them to walk across the bottom of the water. Modern mammals, including humans, evolved from these fish.