A super-rare two-headed gecko has defied the odds to reach four weeks old – with both heads able to feed independently.
The tiny crested gecko, named Simon and Garfunkel, hatched unexpectedly at a husband-and-wife breeding business.
Rockstar Geckos said nothing had appeared unusual about the egg before the two-headed youngster emerged on 29 June.
The breeders initially warned that animals born with the condition tend not to survive for long.
But Simon and Garfunkel are now reportedly thriving, weighing 1.8g and beginning to coordinate their movements.
Rockstar Geckos told Need To Know: “They’re doing great.
“They seem to be doing well, so we’re very happy about that.”
Sharing their four-week milestone online, the breeders wrote: “Here they are at 4 weeks old!
“I chose these photos specifically to show just how tiny they still are, only 1.8 grams.
“It’s hard to grasp until you see them next to a fingernail.”
Simon and Garfunkel had been given a quick bath before the pictures because they had become covered in food after walking across their plate.
Rockstar Geckos, who are based in north-eastern Pennsylvania, added: “On the bright side, their coordination is improving and they’re starting to move a bit more as a team!”
The breeders confirmed both heads are capable of eating without help.
They said: “Both heads eat independently, no assistance needed. Just look at that full tummy!”
Neither head currently appears dominant and their positioning means they cannot reach or bite one another.
X-rays have been considered, but the breeders are still deciding whether the potential benefits outweigh the risks because the gecko is so small and easily stressed by handling.
The condition is known as dicephaly, a rare developmental abnormality in which an animal has two heads.
Its exact incidence among crested geckos is not known.
A peer-reviewed review published in 2010 noted that only four cases of dicephalism had then been documented across three families of lizards, including geckos.
Simon and Garfunkel weighed just under 2g after hatching.
Rockstar Geckos said at the time: “We were definitely very surprised. Nothing seemed different about this egg at all.”
The following day, the tiny reptile shed its skin without help and was placed inside a specially modified enclosure that made its food easier to reach.
An ordinarily healthy crested gecko can live for between 15 and 20 years in human care, but there is no established life expectancy for a two-headed hatchling such as Simon and Garfunkel.
The species itself also has an extraordinary history.
Native to New Caledonia, crested geckos were believed to be extinct for more than a century before being rediscovered in 1994.
The nocturnal reptiles have specialised adhesive toe pads that allow them to climb near-vertical surfaces.
Simon and Garfunkel now have a fan club of people checking in, hoping for their survival and unable to get enough of the geckos.
In response to the four week update, fans cheered on the survival of the two-headed creature.
One person said: “Yay! Such good news! I have been wondering how they are doing. They look like they are thriving!”
Another person commented: “My god this is so incredible. Thank you for keeping us updated, have loved their little journey so far.”
A third person added: “I look for these posts every week to see how they are doing. Love the names.”
Meanwhile, a fourth person wrote: “Okayyyy I need to get them tattooed on me”
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