Experts are astonished as species thought to be extinct for millions of years have “come back to life”.
According to scientists, the discovery of these creatures is regarded as a “Lazarus effect”. The Lazarus effect refers to a phenomenon involving fossil discoveries that describe the reappearance of a taxon after a long period, often millions of years, without any records, leading to the assumption that it was extinct.
1. Laotian Rock Rat
The Laotian rock rat, also known as the Laotian mountain rat (scientific name: Laonastes aenigmamus), is a rodent species found in the Khammuane region of Laos. In 2005, scientists first discovered this mammal in the Hin Nam No National Biodiversity Conservation Area (Khammouane, Laos) and named it.
The Laotian rock rat is the only surviving member of the ancient family Diatomyidae, which was believed to have become extinct about 11 million years ago. (Photo: AZ Animals)
When scientists compared the morphological traits of the Laotian rock rat with fossils from the ancient family Diatomyidae, they confirmed that the Laotian rock rat is the only surviving species from this family, which was thought to have gone extinct in the Miocene epoch, around 11 million years ago.
The Laotian rock rat has a relatively large head and a characteristic bushy tail. An adult Laotian rock rat measures about 26 cm in length (including the tail) and weighs around 400 grams. They typically inhabit rocky outcrops in Khammouane Province (Laos) and some areas of Vietnam. Their preferred diet consists of leaves, grasses, and especially seeds. Occasionally, they also consume insects.
2. Indian Purple Frog
In 2003, biologists discovered a new species of purple frog in western India. It has a pointed nose, tiny eyes, and a plump body measuring 7 cm in length. They subsequently named it Nasikabatrachus sahyadrensis.
The last representative of the Indian purple frog line has existed for over 65 million years. (Photo: AZ Animals)
According to scientists, this frog is not an ordinary toad. Evolutionarily, it belongs to a royal lineage, representing the last of the toads that hopped around the feet of dinosaurs during the Cretaceous period over 65 million years ago.
3. Martialis heureka (Mars Ant)
The Martialis heureka, literally translated as “ant from Mars,” possesses a unique set of characteristics not previously observed in any ant species. While other ant branches have undergone significant changes, Martialis heureka has remained relatively unchanged for over 120 million years. They and their ancestors have lived underground, while other ant species began to conquer the surface long ago.
The Mars Ant has not changed much for over 120 million years. (Photo: AZ Animals)
The Mars Ant measures only about 2 to 3 mm, has a pale color, lacks eyes, but features large mandibles. This ant species was discovered by Christian Rabeling from the University of Texas (Austin) in the Amazon in 2007. They are one of the longest-existing species on the planet.
4. Protoanguilla Palau
In 2011, a team of American and Japanese scientists discovered a new eel species while diving in an underwater cave in the Republic of Palau. This eel was so distinct that scientists had to create a new taxonomic branch to describe its relationship with other eel species. After initial heated debates, genetic analysts confirmed that it is indeed a type of eel, albeit a primitive one.
Protoanguilla Palau was believed to have gone extinct around 70 million years ago. (Photo: AZ Animals)
To classify this new animal, researchers had to create a new genus and species, naming it Protoanguilla Palau in Latin. The research team outlined a “pedigree” of various eel species to illustrate their relationships. This “pedigree” also allowed them to estimate when the ancestor of Protoanguilla Palau diverged from other species.
The study concluded that this new family had evolved independently over the past 200 years, dating back to the early Mesozoic era, when dinosaurs began to dominate the planet. Researchers believe that the Protoanguilla lineage must have been more widely distributed, as the caves they inhabit have existed for 60-70 million years.
5. Horseshoe Crab
The horseshoe crab is an arthropod belonging to the family Limulidae. They are commonly found along the Atlantic coast and are more closely related to spiders, ticks, and scorpions than to crabs. Their ancestors appeared in the Paleozoic era in deep sea environments, later evolving and changing slightly, maintaining that structure for over 445 million years.
Horseshoe crabs evolved and changed slightly, maintaining their structure for over 445 million years. (Photo: AZ Animals)
The horseshoe crab has a hard exoskeleton to protect its body and a long tail used for steering and flipping over if it gets turned upside down. They have ten legs and typically measure about 20-24 inches in length.
One of the most fascinating aspects of horseshoe crabs is their blue blood, which contains a chemical known as Limulus amebocyte lysate (LAL) and Tachypleus amebocyte lysate (TAL). This chemical (a common laboratory reagent) is used to detect bacteria in medical equipment and vaccines, making horseshoe crabs an important species for medical research.
