Weird and Interesting Reptiles - Mole and Worm Lizards

These are two Iberian worm lizards and not blue earthworms.
These are two Iberian worm lizards and not blue earthworms. | Source
World distribution of amphisbaenians, the group of reptiles that includes mole lizards and worm lizards
World distribution of amphisbaenians, the group of reptiles that includes mole lizards and worm lizards | Source

Mole and worm lizards are strange, mainly subterranean reptiles that look a lot like earthworms. They have elongated bodies that appear to be segmented. Worm lizards have no legs and even move like earthworms. Mole lizards have small forelegs but no hind legs. Both types of reptiles have tiny eyes. They live in burrows, which they dig themselves, and are primarily carnivorous.

Mole and worm lizards are vertebrates, unlike earthworms. They belong to the Class Reptilia and the Order Squamata. This order also contains snakes and lizards. Despite their names, however, mole and worms lizards are technically amphisbaenians instead of lizards. The evolutionary relationship between amphisbaenians and lizards is still being investigated. What is known is that amphisbaenians are very unusual reptiles with their own unique characteristics. They are interesting and intriguing animals that are often hard to study in their natural habitat because they live underground.

The Four-Toed Mole Lizard - Bipes canaliculatus

The amphisbaenia was a mythological creature in Ancient Greek culture that had a head at each end of its body. In its earliest form it was snake-like and venomous. Real-life amphisbaenians aren't venomous.

Mole Lizards

There are three species of mole lizards (or four, according to some scientists), all belonging to the genus Bipes and all living in Mexico. They are the only amphisbaenians with legs.

Although at first glance a mole lizard appears to have rings like those of an earthworm, if we look closely we can see that the rings contain scales instead of smooth skin. A mole lizard has a backbone and its internal organs are more advanced than those of an earthworm. Unlike the case in an earthworm, the internal structure of the mole lizard isn't segmented.

A mole lizard's front legs are small, but they are well developed. X-rays show vestigial back legs under the skin. The toes on the front legs have claws. The legs shovel through the sand or soil of the animal's habitat as a burrow is built, acting like the legs of a mole. This behaviour gives the mole lizard its name.

A mole lizard feeds on insect larvae, ants, termites, other underground insects and earthworms. The female produces one to four eggs in summer, which hatch after about two months.

Bipes canaliculatus Digging in the Soil

The Mexican Mole Lizard, or Bipes biporus

The Mexican mole lizard is native to Baja California in Mexico. It's very similar to the four-toed mole lizard shown in the videos above and on the right. The Mexican mole lizard has five toes on each foot, however, and is pale pink in colour instead of pale blue.

Some people describe the Mexican mole lizard as being "cute" or "adorable", which are unusual descriptions for a reptile! The small legs, the blunt-tipped head with tiny eyes and the somewhat awkward movements of the legs on land do give a mole lizard a slightly babyish appearance, as can be seen in the first video of the four-toed mole lizard.

The Mexican mole lizard lacks surface pigment which would protect it from the sun's rays, but this doesn't hurt it. It lives underground and generally comes to the surface only during the night or when the soil is very wet on a dull day.

A preserved Amphisbaena fuliginosa; this attractive worm lizard lives in the northern part of South America and in Trinidad
A preserved Amphisbaena fuliginosa; this attractive worm lizard lives in the northern part of South America and in Trinidad | Source

Worm Lizards

At first it's very tempting to think that worm lizards are earthworms due to the rings around their body and the fact that the rings bunch up and then spread apart as the animals move, just as they do in earthworms. The surprising appearance of a forked tongue flicking in and out of its mouth tells us that a worm lizard is really a reptile, however.

Worm lizards are sometimes known as "two-headed" snakes - just like the mythical amphisbaenia from Ancient Greece - because their head and their tail look quite similar.

The internal anatomy of worm lizards is similar to that of other reptiles and is very different from that of an earthworm. Unlike earthworms, worm lizards and other amphisbaenians have a backbone and lungs, for example, as well as a more advanced heart, brain and nervous system. They also have teeth inside their mouth. The right lung is reduced in size or even absent to accommodate the narrow, elongated shape of the body. In legless lizards and snakes, the left lung is reduced in size instead of the right lung.

A Living Amphisbaena fuluginosa

An Iberian Worm Lizard in Spain

The Iberian Worm Lizard, or Blanus cinereus

The Iberian worm lizard lives in Portugal and Spain. There is considerable variation in the species, which has led some scientists to say that it should really be separated into two different species. Like other amphisbaenians, the Iberian worm lizard lives underground, builds burrows and feeds mainly on insects and insect larvae. The animal is pink, brown or blue in colour.

The Iberian worm lizard has been studied in more depth than many other amphisbaenians. Researchers have discovered that this animal - and perhaps other amphisbaenians - can control its temperature by changing its location underground. It moves into deeper and cooler soil when to gets too hot. On the other hand, it moves underneath rocks when it becomes too cold.

The worm lizard's vision is very poor. The eyes can detect differences in light intensity but not images. The animal has a very good ability to detect the presence of certain chemicals, however. Like snakes and true lizards, the worm lizard picks up chemicals from the air with its flicking tongue and then deposits them in ducts in the roof of its mouth. These ducts lead to the vomeronasal organ in the head, which detects the chemicals.

Iberian worm lizards can tell the difference between prey and non-prey animals by the different chemicals released by the animals. They also seem to be able to differentiate between predators and non-predators by the chemicals that are released. Male and female worm lizards secrete and detect pheromones, which are chemicals that attract the opposite gender and play an important role in mating.

More about Worm Lizards

A Florida Worm Lizard

The Florida Worm Lizard, or Rhineura floridana

Although there are no wild mole lizards living in North America, there is one worm lizard on the continent. It lives in Florida and is appropriately called the Florida worm lizard. Little is known about the biology of this animal.

Like its relatives, the Florida worm lizard spends most of its time underground. Scientists believe that it feeds on insects. It's thought to lay one to three eggs, which hatch after two to three months of development.

The mouth of the Florida worm looks as though it has an overbite. The lower jaw is recessed, which helps to stop sand from entering its mouth. As in many other amphisbaenians, the skin of the Florida worm lizard looks too big for its body and is only loosely attached to it. This worm lizard has the interesting capability of backing into the hole of its burrow tail first when it feels threatened.

Another Florida Worm Lizard

Population Status of Amphisbaenians

Amphisbaenians are fascinating and somewhat bizarre animals. There is a great deal that still needs to be learned about them, including many aspects of their behaviour, their evolutionary relationship with other reptiles and their population size.

There are around 170 to 180 species of amphisbaenians, depending on the classification system that's being used. There may also be undiscovered species. The population size of only a few species has been assessed. These species aren't in any trouble, but this might not be true for all species. Hopefully, more Information about the different amphisbaenians will be obtained soon. They are strange animals that are definitely worth studying.

© 2015 Linda Crampton

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Comments 34 comments

billybuc profile image

billybuc 23 months ago from Olympia, WA

Fascinating! I had no idea. Never heard of them. Thank you for some great information.


AliciaC profile image

AliciaC 23 months ago from British Columbia, Canada Author

Thank you very much for the visit and for being the first commenter, Bill!


DDE profile image

DDE 23 months ago from Dubrovnik, Croatia

A very interesting topic. Reptiles are fascinating creatures. Voted up.


AliciaC profile image

AliciaC 23 months ago from British Columbia, Canada Author

Thank you for the comment, Devika. I appreciate the vote, too.


tobusiness profile image

tobusiness 23 months ago from Bedfordshire, U.K

Alicia, interesting and as always detailed and very well done. I have to admit I didn't linger for too long on the images, I can just about cope with my little friends in the garden, but great information.


AliciaC profile image

AliciaC 23 months ago from British Columbia, Canada Author

Hi, Jo. Thank you for the visit and the comment, especially since reptiles aren't your favourite type of animal! I like reptiles, although I wouldn't like to get too near to the dangerous ones.


FlourishAnyway profile image

FlourishAnyway 23 months ago from USA

Definitely unusual! I loved learning about these strange creatures. A bit creepy, yes, but I don't think I will personally come across them, so I think I am safe. Great hub! You have some of the most interesting topics! Pinning and sharing, voting up and more.


ologsinquito profile image

ologsinquito 23 months ago from USA

Very interesting. The purplish one in your first picture is actually kind of pretty.


AliciaC profile image

AliciaC 23 months ago from British Columbia, Canada Author

Hi, Flourish. Thank you so much for the kind comment, the shares and the vote! Amphisbaenians could be considered creepy, but I think they're also very interesting animals.


AliciaC profile image

AliciaC 23 months ago from British Columbia, Canada Author

I agree, ologsinquito - I love the colour of that worm lizard. Thank you very much for the comment.


MsDora profile image

MsDora 23 months ago from The Caribbean

Your article reminds me of years ago when my son would share his excitement about this kind of stuff. Weird and interesting seems like the best description for these creatures you describe. Thanks for researching and sharing.


AliciaC profile image

AliciaC 23 months ago from British Columbia, Canada Author

Thank you for the comment, Dora. I agree - these animals are definitely weird and interesting!


bdegiulio profile image

bdegiulio 23 months ago from Massachusetts

Hi Linda. How interesting. I had never heard of the Mole and Worm Lizard. Fascinating creatures. Thanks for the education.


AliciaC profile image

AliciaC 23 months ago from British Columbia, Canada Author

Hi, Bill. Thanks for visiting and commenting. I think that the mole and worm lizards are fascinating creatures, too!


BlossomSB profile image

BlossomSB 23 months ago from Victoria, Australia

Thank you for such an interesting article about these creatures. Enjoyed reading.


AliciaC profile image

AliciaC 23 months ago from British Columbia, Canada Author

Thank you very much for the comment, Blossom.


vespawoolf profile image

vespawoolf 23 months ago from Peru, South America

What an interesting category of animals, the amphisbaenians. I´ve seen very little information about them before. I would especially like to see a Mexican mole lizard since they´re cute--probably because they look so tiny and defenseless. Thank you for sharing the information and photos.


AliciaC profile image

AliciaC 23 months ago from British Columbia, Canada Author

Hi, vespawoolf. It's nice to discover that someone else thinks that the Mexican mole lizard is cute! Thank you for the comment.


Genna East profile image

Genna East 22 months ago from Massachusetts, USA

I’d never have guessed from the intro photo that this little fella was a reptile. Who knew? I never heard of this species before. Although I am still not fan of lizards and snake-like critters, I found your article well-researched and quite interesting.


AliciaC profile image

AliciaC 22 months ago from British Columbia, Canada Author

Thanks for the visit and the comment, Genna. I agree - the animal in the introductory photo definitely doesn't look like a reptile!


Mel Carriere profile image

Mel Carriere 22 months ago from San Diego California

An intriguing example of convergent evolution, it is amazing how this reptile has adapted to live in the soil. Thank you for the educational experience.


AliciaC profile image

AliciaC 22 months ago from British Columbia, Canada Author

I agree, Mel - it is an intriguing situation. Thank you for the comment.


Joyfulcrown profile image

Joyfulcrown 22 months ago

Worms and lizards normally make me very squeamish. But your article intrigued me.


AliciaC profile image

AliciaC 22 months ago from British Columbia, Canada Author

Thank you, Joyfulcrown. I'm glad that the article intrigued you, especially considering the way that you feel about worms and lizards!


aviannovice profile image

aviannovice 22 months ago from Stillwater, OK

You have done it again, come up with animals that I have never heard about. You give me such an education in the field. Thanks so much.


AliciaC profile image

AliciaC 22 months ago from British Columbia, Canada Author

Thank you very much, Deb. I appreciate your comment.


GeorgeneMBramlage profile image

GeorgeneMBramlage 22 months ago from southwestern Virginia

An interesting and well-written Hub Page. Photos and videos add a great deal. Unfortunately some of your visual bleed over the margins and under ads etc. in right-hand column.


AliciaC profile image

AliciaC 22 months ago from British Columbia, Canada Author

Thank you for the visit, Georgene. I appreciate your comment. I used the picture and video formats provided by HubPages in this hub. The screen looks fine for me. It's interesting to hear that it doesn't look right to you.


Peggy W profile image

Peggy W 22 months ago from Houston, Texas

I knew nothing about these creatures, so thanks for the education Alicia. Happy Valentine's Day!


AliciaC profile image

AliciaC 22 months ago from British Columbia, Canada Author

Thank you, Peggy! I hope you have a wonderful day.


Pawpawwrites profile image

Pawpawwrites 21 months ago from Kansas

What an amazing group of reptiles. Nature can blow your mind sometimes.


AliciaC profile image

AliciaC 21 months ago from British Columbia, Canada Author

It certainly can, Pawpawwrites! Thank you for the visit and comment.


peachpurple profile image

peachpurple 20 months ago from Home Sweet Home

those pictures look like snakes! awesome hub, never heard of these worms


AliciaC profile image

AliciaC 20 months ago from British Columbia, Canada Author

Thank you very much for the comment, peachpurple. The lizards do look like worms! They are interesting creatures.

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