When worlds collide: Lazarus Taxa

In biology, a taxon (plural: taxa) is a group of one (or more) populations of organism(s), which a taxonomist adjudges to be a unit. Usually a taxon is given a name and a rank, although neither is a requirement. Defining what belongs or does not belong to such a taxonomic group is done by a taxonomist with the science of taxonomy. It is not uncommon for one taxonomist to disagree with another on what exactly belongs to a taxon, or on what exact criteria should be used for inclusion.

in paleontology, a Lazarus taxon (plural taxa) is a taxon that disappears for one or more periods from the fossil record, only to appear again later. The term refers to the story in the Gospel of John, in which Jesus is said to have raised Lazarus from the dead.

So says science, in short, a Lazarus Taxon is an animal or plant that we thought was extinct but has since been re-discovered.

In recent years we have heard a lot about animals that are on the endangered species list, we have eye for the Panda and the Whale, we say awwww when we hear that a rhino or elephant is in need of help and we moarn when we hear another species is gone from this earth  like the Golden toad in 1989

Golden Toad, extinct 1989

However, besides losing animals (and plants, let not forget about plants) we also have learned that we not only lose animals, we have re-discovered animals thought to be extinct for a while, ranging from a few decades to millions of years. Here is a short-list of a few of them, enjoy. 😀

1: the Coelacanth (Latimeria chalumnae)

Coelacanth

Probably the most well known example. The primitive-looking coelacanth (pronounced SEEL-uh-kanth) was thought to have gone efxtinct with the dinosaurs 65 million years ago. But its discovery in 1938 by a South African museum curator on a local fishing trawler fascinated the world and ignited a debate about how this bizarre lobe-finned fish fits into the evolution of land animals.

There are only two known species of coelacanths: one that lives near the Comoros Islands off the east coast of Africa, and one found in the waters off Sulawesi, Indonesia. Many scientists believe that the unique characteristics of the coelacanth represent an early step in the evolution of fish to terrestrial four-legged animals like amphibians.

The most striking feature of this “living fossil” is its paired lobe fins that extend away from its body like legs and move in an alternating pattern, like a trotting horse. Other unique characteristics include a hinged joint in the skull which allows the fish to widen its mouth for large prey; an oil-filled tube, called a notochord, which serves as a backbone; thick scales common only to extinct fish; and an electrosensory rostral organ in its snout likely used to detect prey.

Coelacanths are elusive, deep-sea creatures, living in depths up to 2,300 feet (700 meters) below the surface. They can be huge, reaching 6.5 feet (2 meters) or more and weighing 198 pounds (90 kilograms). Scientists estimate they can live up to 60 years or more.

Their population numbers are, predictably, not well known, but studies in the Comoros suggest only about 1,000 remain there. They are considered an endangered species.

2:Lord Howe Stick Insect (Dryococelus australis)

The Lord Howe Island stick insect (Dryococelus australis) or “land lobster” is a large, flightless stick insect that was, until recently, thought to be extinct. It has a glossy brownish-black exoskeleton with some pale yellow markings where joints and body segments meet.

Females reach over 150 mm in length, while the slightly smaller males are characterised by strongly curved, spiny, muscular hind legs.

As the name suggests, this species was known only from Lord Howe Island, a small volcanic island situated in the Tasman Sea some 800 km north east of Sydney, Australia. It is nocturnal, feeding and moving around only at night, and sheltering in small tree hollows during the day. In 1916, Arthur Lea, a well-known Australian entomologist, visited the island and described seeing as many as 68 stick insects in a single tree hollow.

The Lord Howe Island stick insect is arguably the rarest insect in the world. The species was abundant until sometime after 1918 when a vessel, the “Makembo”, ran aground nearby leading to the introduction of black rats (Rattus rattus) to Lord Howe Island. Within 30 years the stick insect was thought to be extinct due to predation.

In 1964 a group of climbers ventured onto the nearby island of Balls Pyramid. This steep, rocky outcrop is situated approximately 23km south east of Lord Howe Island and is virtually inaccessible. The adventurers made landfall and were able to take some photographs, including one of a recently dead Lord Howe Island stick insect.

No further exploration occurred until 2001 when a group of researchers returned to Balls Pyramid and rediscovered living adults. Today fewer than 30 adult stick insects remain on the Pyramid and the species is recognised as “Critically Endangered” by the IUCN Red List.

3: Banggai Crow (corvus unicolor)

Banggai Crow

The Banggai Crow (Corvus unicolor) is a member of the crow family from Banggai in Indonesia. It is listed as critically endangered by IUCN. It was feared extinct, but was finally rediscovered during surveys on Peleng Island by Indonesian ornithologist Mochamad Indrawan in 2007 and 2008.

It was sometimes considered a subspecies of the Slender-billed Crow, but it is actually rather distinct from this bird, resembling an entirely black Piping Crow overall. The Banggai Crow is a small crow, some 39 cm long and completely black with a pale iris and a short tail.

For more than a century, it was known from only two specimens taken from an unknown island in the Banggai Archipelago – probably in 1884/1885. Visits to the archipelago in 1991 and 1996 yielded no unequivocal records of the species, leading some to believe it was extinct. During a survey conducted between 2007 and 2008 and partially financed by the Zoological Society for the Conservation of Species and Populations (Germany), it was repeatedly seen on Peleng Island[3] and Indonesian ornithologist Mochamad Indrawan caught and photographed two individuals.[4] The validity of the crows on Peleng was not recognized by BirdLife International in its 2009 Red List. Confirmation of the identity based on two specimens from Peleng was made by Pamela C. Rasmussen of the American Museum of Natural History in October 2009.

The total population is estimated at approximately 500 mature individuals, living in mountain forest at altitudes above 500 m. The decline of the Banggai Crow is thought to be primarily due to habitat loss and degradation through agriculture and extraction.

This bird remained a complete enigma for a long time. Listed as Vulnerable in the 1994 IUCN Red List, it was changed to Endangered in 2000. In 2006, the status was considered as Possibly Extinct. This proved to be incorrect and the status was corrected to Critically Endangered in the 2007 Red List. (I could not find a video of the bird)

4: Cuban Solenodon (Solenodon cubanus)

Cuban Solenodon

This primitive insectivore resembles a large stoutly-built shrew. Like its relative the Hispaniolan solenodon (S. paradoxus), this species secretes toxic saliva to subdue its prey. The solenodons diverged from all other mammal groups an incredible 76 million years ago and were, until recently, among the dominant predators of the West Indies. The species was almost wiped out by introduced predators such as dogs, cats and mongooses following European colonisation of Cuba, and was believed to be extinct until a single individual was captured in 2003.

Recent genetic studies have revealed that the solenodons diverged from all other living mammals during the Cretaceous Period, an incredible 76 million years ago. This separation occurred at least as long ago as the branching of many entire mammalian orders (e.g. pangolins versus carnivores, or manatees versus elephants).

Fossil evidence shows that solenodon-like insectivores existed in North America 30 million years ago. They are thought to have originated from North American insectivores that colonised the Greater Antilles by overwater dispersal from Central America or the southeastern United States.

There are only two species of solenodon alive today, the Cuban solendon (S. cubanus) and the Hispaniolan solenodon (S. paradoxus). Two additional species, S. arredondoi and S. marcanoi, are known only from skeletal remains collected from western Cuba and southwestern Hispaniola respectively.

The two living solenodon species are believed to have diverged around 25 million years ago, when northern Hispaniola separated from eastern Cuba. This separation is comparable to the divergence between distinct mammalian families, for example, dolphins versus whales (30 Myr ago), or humans versus Old World monkeys (23 Myr ago). On this basis some researchers argue that the two species should be placed in different genera, with the Cuban solenodon being placed in a distinct genus,Atopogale

Sources used for this article are National Geographic , Listverse.com, Listosaur.com , and of course Wikipedia