Music:

Camiidae webpage: https://camiidae.carrd.co/

-Hymn to the Muse - Ancient Greek Song – Farya Faraji:
https://youtu.be/G1rf-Q6WmNc?si=wEws7T3P9PBVPTyd

-Snail: Bugs odyssey – Camiidae:
https://youtu.be/kF6O4PmuonM?si=sGLn6cd6Nm_2kodL

-Ant: Bugs odyssey – Camiidae:
https://youtu.be/IgVbm8dydgw?si=VkKH5MYyI2PajiPc

-Naraoia: Music for Cambrian animals – Camiidae:
https://youtu.be/53hCTO49ees?si=1uUmcGlch3VZ-9VA

-Ophabinia: Music for Cambrian animals – Camiidae:
https://youtu.be/fP8pSGuvBmM?si=CkpsUnujTJo8pUEK

Sound Effects:

-Strong wind blowing and howling in the middle of the desert of Atacama, in the "moon valley" (Chile) by felix.blume -- https://freesound.org/s/146914/ -- License: Creative Commons 0

-snarling Snake by florianreichelt -- https://freesound.org/s/423454/ -- License: Creative Commons 0

References

“AMPHISBAENA (Amphisbaina) - Two-Headed Serpent of Greek & Roman Legend.” Accessed September 3, 2024. https://www.theoi.com/Thaumasios/Amphisbainai.html.

“Amphisbaena Varia.” Accessed September 9, 2024. https://bioweb.bio/faunaweb/reptiliaweb/FichaEspecie/Amphisbaena%20varia.

“Amphisbaenia.” Accessed September 3, 2024. https://www.ucl.ac.uk/museums-static/obl4he/vertebratediversity/amphisbaenia.html.

“Encyclopædia Britannica, Ninth Edition/Amphisbæna - Wikisource, the Free Online Library.” Accessed September 3, 2024. https://en.wikisource.org/wiki/Encyclop%C3%A6dia_Britannica,_Ninth_Edition/Amphisb%C3%A6na.

Gorzula, Stefan. “Gorzula, S., C. Salazar and D. Rendon (1977) Aspects of the Ecology of Amphisbaena Alba Linnaeus. British Journal of Herpetology, 5: 623-626.,” May 8, 2020.

Guedes, Jhonny J. M., Henrique C. Costa, and Mario R. Moura. “A New Tale of Lost Tails: Correlates of Tail Breakage in the Worm Lizard Amphisbaena Vermicularis.” Ecology and Evolution 10, no. 24 (2020): 14247–55. https://doi.org/10.1002/ece3.7023.

Houle, Alain. “Floating Islands: A Mode of Long-Distance Dispersal for Small and Medium- Sized Terrestrial Vertebrates.” Diversity and Distributions 4, no. 5/6 (1998): 201–16.

“ITIS - Report: Amphisbaenia.” Accessed September 3, 2024. https://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=209626#null.

Jared, Carlos, José Duarte de Barros Filho, Simone G. S. Jared, César Alexandre, Pedro Luiz Mailho-Fontana, Selma M. Almeida-Santos, and Marta Maria Antoniazzi. “Peering into the Unknown World of Amphisbaenians (Squamata, Amphisbaenia): A Summary of the Life History of Amphisbaena Alba.” Acta Zoologica n/a, no. n/a. Accessed September 3, 2024. https://doi.org/10.1111/azo.12490.

Jorge L. Borges, Margarita Guerrero. “La Anfisbena.” In El Libro de Los Seres Imaginarios, 5–6. Buenos Aires: Kier, 1967.

Longrich, Nicholas R., Jakob Vinther, R. Alexander Pyron, Davide Pisani, and Jacques A. Gauthier. “Biogeography of Worm Lizards (Amphisbaenia) Driven by End-Cretaceous Mass Extinction.” Proceedings of the Royal Society B: Biological Sciences 282, no. 1806 (May 7, 2015): 20143034. https://doi.org/10.1098/rspb.2014.3034.

Macey, J. Robert, Theodore J. Papenfuss, Jennifer V. Kuehl, H. Mathew Fourcade, and Jeffrey L. Boore. “Phylogenetic Relationships among Amphisbaenian Reptiles Based on Complete Mitochondrial Genomic Sequences.” Molecular Phylogenetics and Evolution 33, no. 1 (October 1, 2004): 22–31. https://doi.org/10.1016/j.ympev.2004.05.003.

Queiroz, Kevin De, Philip D. Cantino, and Jacques A. Gauthier. Phylonyms: A Companion to the PhyloCode. Edited by Kevin De Queiroz, Philip Cantino, and Jacques Gauthier. 1st ed. Boca Raton : CRC Press, [2019]: CRC Press, 2020. https://doi.org/10.1201/9780429446276.

Reiche, H., L. S. L. Hohl, and O. Rocha-Barbosa. “Food Capture and Escape Behavior of Leposternon Microcephalum Wagler, 1824 (Squamata: Amphisbaenia).” Brazilian Journal of Biology 84 (December 13, 2021): e251255. https://doi.org/10.1590/1519-6984.251255.

Riley, J., J.M. Winch, A.F. Stimson, and R.D. Pope. “The Association of Amphisbaena Alba (Reptilia: Amphisbaenia) with the Leaf-Cutting Ant Atta Cephalotes in Trinidad.” Journal of Natural History 20, no. 2 (April 1, 1986): 459–70. https://doi.org/10.1080/00222938600770361.

Ross Piper. “White Worm Lizard.” In Extraordinary Animals: An Encyclopedia of Curious and Unusual Animals, 144–46. London: Greenwood Press, 2007.

Silveira, Paulo Vitor Portella, and Sérgio de Andrade Nishioka. “Non-Venomous Snake Bite and Snake Bite without Envenoming in a Brazilian Teaching Hospital: Analysis of 91 Cases.” Revista Do Instituto de Medicina Tropical de São Paulo 34 (December 1992): 499–503. https://doi.org/10.1590/S0036-46651992000600002.

Vidal, Nicolas, Anna Azvolinsky, Corinne Cruaud, and S.Blair Hedges. “Origin of Tropical American Burrowing Reptiles by Transatlantic Rafting.” Biology Letters 4, no. 1 (February 23, 2008): 115–18. https://doi.org/10.1098/rsbl.2007.0531.

Script:

Back in the days of the early roman empire, when the troops of Cato were crossing African deserts during their campaign against Julius Caesar, they faced a particularly unsettling creature. It was a snake with two heads, one in the front and the other attached to the tail, depending on which direction the animal wanted to move, one head would work as the main head and the other would follow as a tail, it was a creature able to go in both directions, an amphisbaena (anfisbena), in ancient Greek. It was a very venomous animal, so much “as if one mouth was not enough to poured out all the poison”, according to Plinius the elder[1].

This creature persisted in the medieval bestiaries until its existence was rebutted, as many other ancient ideas, during the scientific revolution, in the XVII century.  The basic rules of nature and anatomy completely forbade the existence of such animal. And thus, alongside with krakens, mermaids and unicorns, the amphisbaena was completely banished to the realm of mythical creatures. We wouldn’t consider its real existence ever again, unless…

-musical intro

Greetings my friend and welcome to “it’s not a monster” on defense of the misunderstood, the despised, the vilified or just… the ugly ones. I am David Andres Quinche.

The first time that I heard this story was in a tale from the book of imaginary beings, By Margarita Guerrero and one of my favorite writers, Jorge Luis Borges. If you like fantasy and also this podcast you should check out that book. But that was not the first time that I heard about the animal, that was years before in college studying biology. Because… yes, the amphisbaena is a real creature.

 But it’s not the venomous and lethal two heads snake described by Romans and ancient Greeks. And today I want to talk to you about that. This time I am not going to reframe a well-known creature with a problematic fame. The amphisbaena is rarely known, but the times that is recognized, is usually blamed with the same sins as the snakes. So, to prevent this, I want to introduce, in a proper manner, a marvelous inhabitant of this world that you might not be familiar with. Today we are going to talk about the Amphisbaenia.

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First things first: the amphisbaenas or worm lizards, are not snakes, neither worms, even though they look a little bit like one. They conform the suborder Amphisbaenia, a group that is divided between 6 families, which in total include more than 200 species. Most of them live in south America and Africa, and some other species in the Caribbean, florida, the mid-east and part of the meditaranean region.[2]

All of them are limbless lizards, except for 3 species in the genus Bipes, which have a couple of specialized tiny forelimbs that look a lot like the claws of a mole. And yes, the suborder Amphisbaenia is part of Squamata, the same order that other Lizards AND Snakes belong to. But they are not snakes, they are more like their distant cousins[3]; actually, you would be surprised by the number of legless lizards that exist which are not snakes.

How do we know this? Well, there are a couple of key traits that set the amphisbaenas apart. Three of the most evident are: First, their lung reduction, because of their elongated body they have undergone  a drastic reduction of the right lung, while in snakes and other limbless lizards this have happened with the left lung; Second, their body scales, they have a ring-like arrangement, one ring of scales after the other through all their bodies, making them look… more like a worm, instead of the typical diagonal overlapping scales in snakes; and third, their brain case, their skull is a very solid and robust, something completely different to the super articulated and flexible skull of snakes[4].

All these traits have something in common, they are strongly related with the lifestyle of the amphisbaena. There is no other lizard so specialized as a burrowing creature. Their elongated body allows them to move easily underground, their tough skull makes their heads a very efficient drilling tool, and the ring disposition of the scales facilitates moving backwards in their tunnels if necessary without too much resistance, this is actually the only burrowing reptile able to do that[5].

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Ok, a burrowing lizard, with strong longitudinal muscles yet no limbs, no striking coloration and with eyes so reduced that their face looks like a cartoon. How is this related with the mythical creature that I mentioned at the beginning. Is this a dangerous creature? Do they bite? Well actually… even though they are not venomous as the ancients said, if they are handled without taking necessary precautions, they can bite… quite powerful for their small size, this is true at least for Amphisbenia alba, one of the most common and better known species[6][7]. However, considering the subterranean habits of these creatures, an encounter of this type is very uncommon. In a survey done in a Brazilian hospital between 1984 and 1990, from 473 cases of reported snake-like bites, only one was caused by an amphisbaena species, Amphisbaena mertensii[8].

Considering their habits and lifestyle, they do not represent a great threat to us. They mostly feed on all kind of small invertebrates, and even in the case of the biggest species, the aforementioned Amphisbaena alba, which can reach up to 80 cm, they don’t feed on anything much bigger neither, no bigger than some small vertebrates that they prey on in an opportunistic way[9].

And talking about the diet. There is actually something interesting here. In some regions of South America, the amphisbaena are also known by the name of Mother of ants[10]. Both the locals and some field reports suggested a strong association between these lizards and leafcutter ants, with cases of these lizards even laying their eggs inside these ants’ nests[11]. Some scientists first believed that the amphisbaena frequented these nests because they feed on ants. But if that where so, the ants would have a more hostile reception to the amphisbaena, which is not the case. There is another explanation. When they visit these ants’ nests, most of the time the amphisbaenas are found in the lower chambers; not the ones that host the fungi crops or the ants’ larvae, which would be an obvious target, but the refuse chambers. There, it seems that they feed on beetle larvae, which are a common dweller in the ants’ nests. When they are done with the beetles, they may go back to their own tunnels, or they can go up to the surface and try to find another ant nest.

Now you might ask, how the heck a semi-blind legless lizard could find an ant nest? Well, in the same way that ants themselves do it. The amphisbaenas are able to smell ant pheromones, so they can find and follow the same tracks that the ants use for their orientation[12]. Depending how do we see it, we can perceive this amphisbenid-ant interaction as an opportunistic and inoffensive visit from the first ones, or even as a symbiotic cooperation between both, where the amphisbaena feeds and gets rid of potential parasites. 

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Now that we know that the amphisbaena is not venomous and mostly eats bugs… what about the two heads thing? was it just an ancient superstition? Well, it kind of has an explanation. 

As many other lizards, the amphisbaena presents a behavior known as urotomy[13]: when a predator is attacking, they are able to detach their tails, sacrificing a part of their body as a distraction for the predator in order to being able to escape. But predators could be smart, those that specialize in this kind of snake-like preys know that frequently the best strategy is go for the head of the victim. Therefore, if you as a prey manage to confuse your attackers about which part of your body is your head and which one is your tail, and if on top of that you are also able to detach your tail as a decoy in case that the predator catches you, you have a very solid scape strategy.

The tail of the amphisbaena is not slim at the tip like the snakes, it has a blunt end, so it looks someway similar than their heads. Some species, like our friend Amphisbaena alba, take advantage of this and when they feel threatened, they do something called horseshoe display[14], which consist in raising both the head and the tail in a menacing way, making difficult to distinguish one extreme of the animal from the other.

There are other species, like the small Leposternon Microcephalum, who take this one step further. They can slither backwards as easily as they do forwards. This is very useful when they need to go backwards burrowing their tunnels, but they also use it as an escape strategy[15], scaping quickly in one direction… to suddenly going backwards, without any way to know quickly what is the real head of the animal. Now you might imagine why the ancients got so confused when they saw these creatures moving.

There is a final thought that I want to share with you about the amphisbaena. The ironic fact that being such a good fossorial creature allowed them to, in the past,  conquest new lands… by sailing. As I mentioned before, this group is distributed between the Americas, Europe and Africa, lands very far from each other. This was initially explained by continental drift, it was thought that the amphisbaena ancestor appeared when all these lands were the same continent, and after the continents started to split more and more, these different amphisbaena groups got isolated and started to diversify.

But some genetic studies have suggested that this diversification process started a little bit later, after the continents had drifted apart. There should have been a way in which this creature crossed the sea when there was already some distance between the continents, and that way… is rafting[16].

This is the name of a process in which a chunk of soil and vegetation breaks away from the mainland, mostly because of erosion, and is driven away by the currents and winds to other island or even continents, carrying within unexpected passengers [17]. Imagine a huge tree that, because of the ground wear or a big storm, falls off from a cliff into the sea or a big river, dragging with it a big chunk of dirt and vegetation between its thick roots. Between these roots, some animals have been dragged too, maybe some insects… maybe our amphisbaena. And since our friend is a reptile with a very quiet lifestyle, they could expend weeks or even months without extra water or food until reach land again. According with some researches, I quote “The odds of any particular tree or raft resulting in a successful dispersal may be millions to one, but with millions of trees washed out to sea over millions of years, the odds could be relatively high”[18].

And this is the amphisbaena, a small but tough creature, simple and basic in its shape yet able to move in ways that no other animal could. Quiet with the friends but strong biter with the foes, an expert miner… and accidental sailor.

There are still a lot of things that we don’t know about the amphisbaena, most of the stuff that we have learned is about those species that are easier to spot: the bigger ones and those who spend more time on the surface and considering how special already are those ones, Who knows which amazing adaptations and behaviors hide the species more elusive, those that rarely abandon the warm protection of their deep subterranean abodes.

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You can find references and extra material at the description. This episode was produced by me, David Quinche Giraldo.

Thanks for listening! And see you next time.

[1] Margarita Guerrero Jorge L. Borges, “La Anfisbena,” in El Libro de Los Seres Imaginarios (Buenos Aires: Kier, 1967), 5–6; “AMPHISBAENA (Amphisbaina) - Two-Headed Serpent of Greek & Roman Legend,” accessed September 3, 2024, https://www.theoi.com/Thaumasios/Amphisbainai.html; “Encyclopædia Britannica, Ninth Edition/Amphisbæna - Wikisource, the Free Online Library,” accessed September 3, 2024, https://en.wikisource.org/wiki/Encyclop%C3%A6dia_Britannica,_Ninth_Edition/Amphisb%C3%A6na.

[2] J. Robert Macey et al., “Phylogenetic Relationships among Amphisbaenian Reptiles Based on Complete Mitochondrial Genomic Sequences,” Molecular Phylogenetics and Evolution 33, no. 1 (October 1, 2004): 22–31, https://doi.org/10.1016/j.ympev.2004.05.003.

[3] “ITIS - Report: Amphisbaenia,” accessed September 3, 2024, https://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=209626#null.

[4] “Amphisbaenia,” accessed September 3, 2024, https://www.ucl.ac.uk/museums-static/obl4he/vertebratediversity/amphisbaenia.html; Kevin De Queiroz, Philip D. Cantino, and Jacques A. Gauthier, Phylonyms: A Companion to the PhyloCode, ed. Kevin De Queiroz, Philip Cantino, and Jacques Gauthier, 1st ed. (Boca Raton : CRC Press, [2019]: CRC Press, 2020), https://doi.org/10.1201/9780429446276.

[5] Carlos Jared et al., “Peering into the Unknown World of Amphisbaenians (Squamata, Amphisbaenia): A Summary of the Life History of Amphisbaena Alba,” Acta Zoologica n/a, no. n/a, accessed September 3, 2024, https://doi.org/10.1111/azo.12490.

[6] Stefan Gorzula, “Gorzula, S., C. Salazar and D. Rendon (1977) Aspects of the Ecology of Amphisbaena Alba Linnaeus. British Journal of Herpetology, 5: 623-626.,” May 8, 2020.

[7] Ross Piper, “White Worm Lizard,” in Extraordinary Animals: An Encyclopedia of Curious and Unusual Animals (London: Greenwood Press, 2007), 144–46.

[8] Paulo Vitor Portella Silveira and Sérgio de Andrade Nishioka, “Non-Venomous Snake Bite and Snake Bite without Envenoming in a Brazilian Teaching Hospital: Analysis of 91 Cases,” Revista Do Instituto de Medicina Tropical de São Paulo 34 (December 1992): 499–503, https://doi.org/10.1590/S0036-46651992000600002.

[9] Gorzula, “Gorzula, S., C. Salazar and D. Rendon (1977) Aspects of the Ecology of Amphisbaena Alba Linnaeus. British Journal of Herpetology, 5”; Jared et al., “Peering into the Unknown World of Amphisbaenians (Squamata, Amphisbaenia).”

[10] Jared et al., “Peering into the Unknown World of Amphisbaenians (Squamata, Amphisbaenia).”

[11] “Amphisbaena Varia,” accessed September 9, 2024, https://bioweb.bio/faunaweb/reptiliaweb/FichaEspecie/Amphisbaena%20varia.

[12] J. Riley et al., “The Association of Amphisbaena Alba (Reptilia: Amphisbaenia) with the Leaf-Cutting Ant Atta Cephalotes in Trinidad,” Journal of Natural History 20, no. 2 (April 1, 1986): 459–70, https://doi.org/10.1080/00222938600770361; Ross Piper, “White Worm Lizard.”

[13] Jhonny J. M. Guedes, Henrique C. Costa, and Mario R. Moura, “A New Tale of Lost Tails: Correlates of Tail Breakage in the Worm Lizard Amphisbaena Vermicularis,” Ecology and Evolution 10, no. 24 (2020): 14247–55, https://doi.org/10.1002/ece3.7023.

[14] Jared et al., “Peering into the Unknown World of Amphisbaenians (Squamata, Amphisbaenia)”; Ross Piper, “White Worm Lizard.”

[15] H. Reiche, L. S. L. Hohl, and O. Rocha-Barbosa, “Food Capture and Escape Behavior of Leposternon Microcephalum Wagler, 1824 (Squamata: Amphisbaenia),” Brazilian Journal of Biology 84 (December 13, 2021): e251255, https://doi.org/10.1590/1519-6984.251255.

[16] Nicholas R. Longrich et al., “Biogeography of Worm Lizards (Amphisbaenia) Driven by End-Cretaceous Mass Extinction,” Proceedings of the Royal Society B: Biological Sciences 282, no. 1806 (May 7, 2015): 20143034, https://doi.org/10.1098/rspb.2014.3034; Nicolas Vidal et al., “Origin of Tropical American Burrowing Reptiles by Transatlantic Rafting,” Biology Letters 4, no. 1 (February 23, 2008): 115–18, https://doi.org/10.1098/rsbl.2007.0531.

[17] Alain Houle, “Floating Islands: A Mode of Long-Distance Dispersal for Small and Medium- Sized Terrestrial Vertebrates,” Diversity and Distributions 4, no. 5/6 (1998): 201–16.

[18] Longrich et al., “Biogeography of Worm Lizards (Amphisbaenia) Driven by End-Cretaceous Mass Extinction.”