The term Lazarus Species (or Lazarus Taxon) refers to a phenomenon in paleontology and biology where an organism disappears from the fossil record for a significant period—often millions of years—only to reappear later in the fossil record or be discovered alive in the modern day. The name is a direct biblical allusion to the story of Lazarus of Bethany, who was supposedly resurrected by Jesus 4 days after his death. In the scientific context, it describes a species that was presumed “dead” (extinct) by humanity, only to “rise” again when living specimens are miraculously found. These rediscoveries challenge our understanding of extinction and highlight the limitations of the fossil record.

Fossil Records – Hiding in Plain Sight

To understand how a species can “disappear,” one must first appreciate the imperfection of the fossil record. Fossilization is an incredibly rare event requiring specific environmental conditions—rapid burial, lack of oxygen, and mineral-rich waters. Consequently, there are massive gaps in the geological strata where no fossils of a particular group are preserved. A species might continue to exist in a “refugium”—a specific, isolated geographic region—without leaving a trace that paleontologists can find later. When the species finally reappears in the rock layers or is found alive by explorers, it creates the illusion that it vanished and returned, when in reality, it was simply hiding in plain sight.

The Elvis Taxon

It is important to distinguish a true Lazarus species from what scientists call an “Elvis Taxon.” An Elvis Taxon is a look-alike species that has evolved to resemble an extinct species through convergent evolution—impersonating the original much like an Elvis impersonator. A true Lazarus species is not an impersonator; it is the original lineage itself, surviving against the odds. This distinction is crucial because it underscores genetic continuity. The survival of these animals often links the modern world directly to ancient epochs, providing living windows into the biology of the deep past.

The Coelacanth

The most famous example, often considered the “king” of Lazarus species, is the Coelacanth. For decades, scientists believed this order of lobe-finned fish had gone extinct roughly 66 million years ago, vanishing alongside the non-avian dinosaurs. That changed in 1938 when a museum curator named Marjorie Courtenay-Latimer discovered a strange, blue, limb-finned fish in a trawler’s catch off the coast of South Africa. The discovery sent shockwaves through the scientific community. The Coelacanth was not just alive; it was anatomically nearly identical to its ancient ancestors, proving that some lineages could survive virtually unchanged for eons in the deep ocean’s stability.

The Lord Howe Island Stick Insect

On land, the Lord Howe Island stick insect, also known as the “tree lobster,” offers a more recent and dramatic tale of resurrection. Native to Lord Howe Island between Australia and New Zealand, this large, flightless insect was thought to have been wiped out by invasive and infamous black rats in the 1920s. However, in 2001, scientists scaled Ball’s Pyramid—a jagged, volcanic sea stack miles away—and found a tiny surviving population clinging to a single Melaleuca bush. This rediscovery is a favorite in scientific circles because it demonstrates how life can cling to existence in the most precarious and unlikely of niches.

Chacoan Peccary

Another remarkable mammal is the Chacoan peccary, locally known as the tagua. In 1930, fossils of this pig-like creature were described, and it was assumed to have gone extinct thousands of years ago during the Pleistocene era. Shockingly, in 1971, researchers discovered that the animal was actually quite well-known to the indigenous people of the Gran Chaco region in Paraguay, Bolivia, and Argentina. It was alive and well, merely overlooked by Western science. This highlights a common theme in Lazarus discoveries: local knowledge often predates scientific “discovery” by centuries.

The Takahe

In the avian world, the Takahe of New Zealand serves as a classic conservation success story. This unique, flightless bird with vibrant blue and green plumage was officially declared extinct in 1898 due to overhunting and introduced predators. However, a determined physician named Geoffrey Orbell refused to believe they were gone. In 1948, after years of searching, he rediscovered a small population hiding in the remote Murchison Mountains of the South Island. Today, the Takahe is intensely managed, with its population slowly recovering, illustrating how Lazarus species often require immediate protection upon rediscovery.

Bermuda Petrel

Similarly, the Bermuda petrel, or cahow, was thought to have been driven to extinction by early Spanish and English settlers in the early 1600s. For over 3 centuries, the bird was a ghost, absent from the record until a surprising rediscovery in 1951. Conservationists found a handful of nesting pairs on rocky, inhospitable islets where humans couldn’t reach them. The cahow’s recovery is 1 of the most inspiring chapters in science, involving the construction of artificial concrete burrows and the translocation of chicks to safer islands like Nonsuch Island to rebuild the population from the brink of oblivion.

Laotian Rock Rat

A more recent addition to the Lazarus list is the Laotian rock rat, or the Kha-nyou. Discovered in 2005, not in the wild, but on a table in a food market in Laos, this squirrel-like species of rodent baffled scientists. DNA and morphological analysis revealed that it was not just a new species, but the sole survivor of the family Diatomyidae, which was thought to have gone extinct 11 million years ago. The discovery was akin to finding a living saber-toothed cat; it represented an entire evolutionary branch that was thought to have been pruned from the tree of life ages ago.

Monito del Monte

South America hosts another “living fossil,” the Monito del Monte, or “little monkey of the bush.” While it looks like a small possum, it is actually more closely related to Australian marsupials than to those in the Americas. It is the only surviving member of the order Microbiotheria, a lineage believed to have largely vanished millions of years ago. Its existence supports the theory that marsupials migrated from South America to Australia via Antarctica when the continents were still connected, making it a crucial piece of the biogeographical puzzle.

Habitats

The common thread among these Lazarus species is their habitat: they almost always inhabit remote, inaccessible, or extreme environments. The coelacanth lives in deep-sea caves; the takahe in rugged mountains; the tree lobster on a volcanic spire. These isolated refuges act as shields against the threats that wiped out their widespread relatives—usually human expansion, climate shifts, or invasive predators. Their survival is not accidental but a result of their seclusion, allowing them to persist in “time capsules” while the rest of the world changes around them.

The Resiliency of Animals

Ultimately, the concept of the Lazarus Species serves as a beacon of hope in conservation biology. It reminds us that nature is resilient and that our knowledge of the natural world is far from complete. However, it also serves as a warning. Most Lazarus species are rediscovered with tiny, fragile populations that are incredibly vulnerable to extinction—this time, permanently. When Critter Science highlights these animals, it is not just to marvel at their return, but to emphasize the urgent responsibility we have to ensure their “second life” does not end at the hands of humanity.