Evolution is a biological arms race between predator, prey and environment... but some organisms have remained similar (if not outright the same) for millennia. Check out...
1. The Chimeric Elephant SharksDespite being called a shark, this primitive fish is actually a chimera - a precursor of both sharks and rays. One of the earliest jawed vertebrates, the elephant shark sports a huge snout that it uses to hunt for shellfish buried in the sand off the coast of Australia and New Zealand. Though technically harmless to humans, it does sport a sharp dorsal spike for defence.
This creature has changed very little over 420 million years. As a result, it offers insight into the genetics of early animals. For example, most animals possess multiple types of white blood cell, including both killer T cells (that destroy bacterium and infected cells) and helper T cells that identify infection and help regulate the immune response. Elephant sharks lack helper T cells, suggesting that they were a later evolution of the immune system.
This creature resembles a strange blend of eel and "normal" fish characteristics, having a fairly large head and compact body surrounded by a merged fin. Not only are they primitive by modern standards, they are less evolved than many other fossil eels. Researchers suggest that they diverged from their relatives over 200 million years ago.
It seems that they have found an effective niche. One aardvark fossil found in the Djurab desert of Chad dates from 4 to 5.5 million years ago. It is almost identical to the modern aardvark - though it does have slightly larger teeth and slightly shorter paws.
The gladiators have been around a long time - examples have been found in Baltic amber and in Chinese fossils dating from 165 million years ago. Due to the widespread distribution of fossils, scientists believe that gladiator bugs were much more widespread before climate change or other extinction events confined them to Africa.
5. The Dawn RedwoodRising above the forests of China, these conifers are one of the smallest metasequoias but still tower above most other trees. The dawn redwood was one of the most widely distributed trees of the Tertiary Period (66 to 2.6 million years ago) with examples found in Asia, America and Greenland. These titans were thought to have gone extinct 20 million years ago, but in 1944 a living example was found in Szechuan, China. It seems that a small population of them still survive, providing locals with wood for building and leaves for animal fodder.
The dawn redwood has been used by researchers extrapolating the climate of pre-history. Anywhere the metasequoias thrived would have had conditions similar to those enjoyed by modern Dawn Redwoods - so their fossils indicate a humid climate with summer rain. On another note, seeds sent to Cambridge Botanic Garden in 1949 produced the first dawn redwood in Britain since the Mesozoic era - or time of the dinosaurs.
The particularly rare Allonautilus scrobiculatus (there has been 30 years between sightings) lives at a depth of 200 meters and seems to exist in only a few locations, such as Papa New Guinea. Researchers had to tie fish and chicken to a camera and drop it into the depths before they got a glimpse of the elusive creature.
The Chinese giant salamander grows up to 6 feet in length and spends most of its time under water. Despite this, it possesses no gills - the salamander absorbs oxygen directly through the skin. They also possess vibration-sensitive nodes running down the sides of their body, allowing them to "feel" prey moving in the water around them.
Unfortunately, attempts to introduce captive-reared giant salamanders to the wild have met with limited success. One study found that over half of the individuals released into Chinese waterways were dead within a year and a half.
This creature isn't actually a squid or an octopus, though it shares characteristics with both. For example, the creature sprays bioluminescent goo instead of ink when threatened - in the darkness of the mesopelagic zone, this can confuse predators and act a bit like the chaff launched by warplanes to fool missiles. It can also expose the underside of its cape, displaying sharp spines attached to its tentacles. These strategies seem to have worked out, as "modern" vampire squid have existed in the fossil record for 30 million years!
- The Chimeric Elephant Sharks
- The Precursor Eels
- The Ancient Aardvarks
- The Deadly Gladiator Bugs
- The Dawn Redwood
- The Elegant Nautiloids
- The Giant Salamanders
- The Eerie Vampire Squid
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| Nautiloids are an ancient group... (aravakense) |
1. The Chimeric Elephant SharksDespite being called a shark, this primitive fish is actually a chimera - a precursor of both sharks and rays. One of the earliest jawed vertebrates, the elephant shark sports a huge snout that it uses to hunt for shellfish buried in the sand off the coast of Australia and New Zealand. Though technically harmless to humans, it does sport a sharp dorsal spike for defence.
This creature has changed very little over 420 million years. As a result, it offers insight into the genetics of early animals. For example, most animals possess multiple types of white blood cell, including both killer T cells (that destroy bacterium and infected cells) and helper T cells that identify infection and help regulate the immune response. Elephant sharks lack helper T cells, suggesting that they were a later evolution of the immune system.
2. The Precursor Eels
Recently discovered in an undersea cave in the Pacific Ocean in Republic of Palau, the primitive eel-like Anguilliformes: Protanguillidae seems to have weathered a eons beneath the waves.This creature resembles a strange blend of eel and "normal" fish characteristics, having a fairly large head and compact body surrounded by a merged fin. Not only are they primitive by modern standards, they are less evolved than many other fossil eels. Researchers suggest that they diverged from their relatives over 200 million years ago.
3. The Ancient Aardvarks
Snuffling through the dust as it searches for ants, the aardvark looks like it was put together from spare parts. A pig-like snout protrudes from a kangaroo head, and there is something rabbit-like about the body. They hail from South Africa, where their name roughly translates to "earth pig." These small (50-inch body) creatures subsist on ants grubbed up with their claws and lapped up with their 12-inch-long tongues. Their tough skin protects them from ant-bites, and they rarely need to drink - juicy insects provide all the liquid they need.It seems that they have found an effective niche. One aardvark fossil found in the Djurab desert of Chad dates from 4 to 5.5 million years ago. It is almost identical to the modern aardvark - though it does have slightly larger teeth and slightly shorter paws.
4. The Deadly Gladiator Bugs
Stalking through tall grass, this cricket-like insect makes a swift meal of any other arthropods that cross its path. Sometimes called gladiator bugs or heelwalkers, the African manophasmatodea resemble stick insects. Unlike their slow-moving look-alikes, they are carnivorous. Like an alien in a sci-fi horror film, gladiator bugs hunt at night and grab prey in their raptorial front legs.The gladiators have been around a long time - examples have been found in Baltic amber and in Chinese fossils dating from 165 million years ago. Due to the widespread distribution of fossils, scientists believe that gladiator bugs were much more widespread before climate change or other extinction events confined them to Africa.
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| Redwoods really do look the part of a living fossil! (USA-Reiseblogger) |
5. The Dawn RedwoodRising above the forests of China, these conifers are one of the smallest metasequoias but still tower above most other trees. The dawn redwood was one of the most widely distributed trees of the Tertiary Period (66 to 2.6 million years ago) with examples found in Asia, America and Greenland. These titans were thought to have gone extinct 20 million years ago, but in 1944 a living example was found in Szechuan, China. It seems that a small population of them still survive, providing locals with wood for building and leaves for animal fodder.
The dawn redwood has been used by researchers extrapolating the climate of pre-history. Anywhere the metasequoias thrived would have had conditions similar to those enjoyed by modern Dawn Redwoods - so their fossils indicate a humid climate with summer rain. On another note, seeds sent to Cambridge Botanic Garden in 1949 produced the first dawn redwood in Britain since the Mesozoic era - or time of the dinosaurs.
6. The Elegant Nautiloids
Drifting through ocean waters with a beautiful and buoyant shell, these mollusks have outlasted most of their contemporaries. Despite this, a study of Nautilus pompilius revealed a lifespan shy of 6 years and a relatively spread-out low-density population. This leaves them in a precarious position, vulnerable to climate change, predation or human exploitation.The particularly rare Allonautilus scrobiculatus (there has been 30 years between sightings) lives at a depth of 200 meters and seems to exist in only a few locations, such as Papa New Guinea. Researchers had to tie fish and chicken to a camera and drop it into the depths before they got a glimpse of the elusive creature.
7. The Giant Salamanders
Lying in wait at the bottom of a fast flowing stream, this man-sized amphibian waits for food to swim to it. The giant salamander is considered a living fossil, but the odds of it remaining so are poor. Despite existing for the past 170 million years, they are viewed as an exotic food and served as a Chinese delicacy. A fully grown one can fetch around $1,500 US dollars.The Chinese giant salamander grows up to 6 feet in length and spends most of its time under water. Despite this, it possesses no gills - the salamander absorbs oxygen directly through the skin. They also possess vibration-sensitive nodes running down the sides of their body, allowing them to "feel" prey moving in the water around them.
Unfortunately, attempts to introduce captive-reared giant salamanders to the wild have met with limited success. One study found that over half of the individuals released into Chinese waterways were dead within a year and a half.
8. The Eerie Vampire Squid
Swooping out of the inky depths, this dramatically named squid is completely harmless, relying on trickery to keep it safe. Vampyroteuthis infernalis or "the vampire squid from hell" is an inhabitant of the deep ocean. Blood red, it grows webs between its tentacles that give it an ominous look reminiscent of the wings of a bat or an opera cloak. Ironically its pretty harmless, feeding on "marine snow" made up of plankton, algae and other bits of detritus slowly falling to the ocean floor.This creature isn't actually a squid or an octopus, though it shares characteristics with both. For example, the creature sprays bioluminescent goo instead of ink when threatened - in the darkness of the mesopelagic zone, this can confuse predators and act a bit like the chaff launched by warplanes to fool missiles. It can also expose the underside of its cape, displaying sharp spines attached to its tentacles. These strategies seem to have worked out, as "modern" vampire squid have existed in the fossil record for 30 million years!
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