Pandoravirus: Viruses disguised as cells
In 1998, a team of researchers at Essen University (now merged with the University of Duisburg) observed a mysterious parasite infected with amoeba. This phenomenon made scientists at that time feel very confused, they speculate that this could be an ancient bacterium or a distant relative of the bacteria.
In 2013, Jean-Michel Claverie and his team at Aix-Marseille University in France described a new giant virus called Pandora virus. In a subsequent document search, they found that German researchers had encountered a similar life form, but they did not realize the nature of their viruses.
Most known viruses are extremely small in shape, their biological structure contains at most several hundred genes, while Pandora virus is completely different, it has a very large size, biological shape. When viewed through a microscope, it looks like an oval pot and contains thousands of genes. What is even more surprising is that 93% of the genes are all unknown to humans, so it can be seen that the virus is completely different from any microorganism or life form. known another. So it is not surprising that scientists have a headache because they cannot classify them.
Collodictyon triciliatum: Alone a branch
In biology, phenotypic simplicity does not mean that it is understandable: it is an organism made up of only one cell, but researchers do not know where to place it in a gene-producing plant.
Collodictyon triciliatum was first found in silt in a lake near the city of Oslo, Norway in 1865. Kamran Shalchian-Tabrizi and colleagues at the University of Oslo in Norway believe that this oval cell looks like an ordinary amoeba, but in fact, far from that appearance they hide many things that people have never known.
If its DNA is classified in the eukaryotic domain because its DNA is encapsulated in the nucleus, its morphology does not correspond to any species of this ecoregion.
Therefore, Collodictyon triciliatum can be an intermediary form before eukaryotes form two main branches: a flagellate (Unikont) and dinoflagellates (Dinoflagellata).
This has been further confirmed in genetic analysis. In other words, scientists need to create a separate classification for this cell type of organism. The discovery of Collodictyon triciliatum has given people a deeper understanding of the evolution of eukaryotes.
Hallucigenia sparsa: Animals with “no head or tail”
In 1977, when the English paleontologist Simon Conway Morris saw these strange shaped fossils from the Burgess shale quarry in Canada, he thought the creatures were special and unlike any species. Which has been found before.
They were later named Hallucigenia sparsa (meaning “daydreaming”) and were described as follows: tubular body, standing with 7 “long legs” on their back, with a row of “tentacles” “on the front and 7 pairs of pliers legs below. Small creature, a few centimeters in length and only thicker than a hair. Scientists have described this mysterious creature before, but because its head and tail are similar, they have not yet determined the detailed characteristics.
However, determining the taxonomy of this creature became a nightmare in the paleontological world, because scientists could not find out where they came from, nor how they ate and moved. them.
Until 1991, Lars Ramskold and Hou Xianguang, who was also working at the Swedish Natural History Museum at the time, suddenly thought of reshaping them and recreating the pigment that showed 7 pairs. ” long legs “on the back are actually thorns and act as a body protector.
The change in perspective allowed the “strange insects” to merge into the group of leaf-footed animals and can trace their ancestral origins: these strange terrestrial animals look like worms, but they are actually related to arthropods (including insects).
A study of the structure of the strange worm foundation published in the summer of 2014 seems to provide strong support for this hypothesis …
According to later research, scientists found that Hallucigenia sparsa is a common ancestor of velvet worms and a member of the ecdysozoan group of animals (including arthropods, velvet worms, water bears). They date from the Cambrian boom, the period when most major animal groups first appeared on Earth.
Dendrogramma: Looks like mushrooms but not mushrooms
These sea creatures are shaped like mushrooms, but they are animals. Jorgen Olesen of the National Museum of Natural History in Copenhagen, Denmark and his colleagues named it Dendrogramma and tried to figure out what kind of animal they were.
18 existing Dendrogramma specimens were collected at depths of 400 to 1,000 meters in Australian waters in 1986. Their shape is reminiscent of jellyfish and their close relatives because both have a mouthpiece that can be used. Used for both food absorption and excretion.
However, apart from the above, Dendrogramma has no tentacles, and sensor cells or other features related to jellyfish. And it seems that the taxonomy of this species is still a headache to many scientists. Should dendrogramma be considered a separate branch of a genetically engineered tree?
DNA analysis can give us some suggestions. However, after 28 years of storage in special solutions, every molecular test became impossible. And at the present time it is still not possible to search for a new specimen of this species.