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Strange Animals Podcast

Strange Animals Podcast

Auteur(s): Katherine Shaw
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A podcast about living, extinct, and imaginary animals! Nature et écologie Science Sciences biologiques
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  • Episode 445: Salinella
    Aug 11 2025
    It's a tiny mystery animal! Further reading: Salinella – what the crap was it? Some of Frenzel's drawings of Salinella: Show transcript: Welcome to Strange Animals Podcast. I’m your host, Kate Shaw. Johannes Frenzel was a German zoologist in the 19th century. He worked in Argentina for several years, studying microscopic and near-microscopic animals, and seemed to be a perfectly good scientist who did good work but didn’t make a real splash. But these days he’s remembered for a mystery animal that is still causing controversy in the scientific community. Frenzel described a strange worm-like animal he named Salinella salve in 1892, and Salinella hasn’t been seen since. According to Frenzel’s description of it, Salinella is very different from every other animal known. It’s so different, in fact, that some scientists think Frenzel just made the whole thing up. In 1890 or 1891, a colleague gave Frenzel a soil sample reportedly from the salt pans in Argentina. We don’t know exactly where it came from, just that it’s somewhere in the Río Cuarto region. Frenzel put the sample in an aquarium and added water, although apparently some iodine got mixed in too, either on purpose or maybe by accident. Then he forgot all about the sample for a few weeks. It wasn’t covered and Frenzel reported that some dead flies had fallen into the aquarium. When Frenzel finally got around to examining the sample, he discovered something he had never seen before. No one else had either, before or since. He said it was a worm-like animal about 2 millimeters long, and there wasn’t just one of them. There were quite a few in the sample, some in the soil and some attached to the glass. When he studied the tiny worms, he discovered they had a very basic, very unusual body plan. It was basically just a tube open at both ends, with a single layer of cells around the interior sac. Each cell was covered with cilia on both the exterior side of the animal and the interior side. Cilia are hair-like structures, and salinella used them to move around, a method of propulsion called ciliary gliding. It didn’t have any organs or even tissues—basically nothing you’d expect even in a very simple animal. It reproduced by splitting down the middle, called transverse fission. Assuming Frenzel was describing a real animal, and was describing it accurately, this body plan is unlike any other animal known. It’s most similar to what scientists think the body plan was of the precursors to sea sponges. It’s also similar in some ways to a group of parasitic animals called Mesozoa, which are wormlike, very simple, only a few millimeters long at most, and which have an outer layer of ciliated cells. Mesozoans aren’t well understood and most scientists these days think the group is made up of animals that aren’t closely related to each other. Salinella has sometimes been considered a mesozoan, but it’s still not that close of a match. Frenzel took detailed notes and made careful drawings of Salinella, and compared it to known animals like protozoans. His description of the animal is solid, and he described many other animals in his career that are well-known to scientists today. The main reason some scientists now think Frenzel made Salinella up is because it’s so weird and no one has been able to find it since. Frenzel died in 1897 without ever having the chance to look for more specimens. In 1963 an American biologist placed Salinella in its own phylum, which he named Monoblastozoa. In the early 2010s, a team of German scientists visited various saline lakes in Argentina and Chile in hopes of finding Salinella specimens, but without luck. The area where the original soil sample came from has mostly been converted to farmland, so if Salinella was restricted to that one spot, it might well be extinct now. So what happened to the type specimens that Frenzel collected? We don’t know. They vanished sometime between 1891 when Frenzel moved b...
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    7 min
  • Episode 444: Diskagma and Horodyskia
    Aug 4 2025
    It's Invertebrate August! These creatures are the most invertebrate-y of all! Further reading: Dubious Diskagma Horodyskia is among the oldest multicellular macroorganisms, finds study A painting of diskagma, taken from the top link above: Little brown jug flowers (not related to diskagma in any way!): Show transcript: Welcome to Strange Animals Podcast. I’m your host, Kate Shaw. This episode started out as the March 2025 Patreon episode, but there was more I wanted to add to it that I didn’t have time to cover in that one. Here’s the expanded version to kick off Invertebrate August, which also happens to be episode 444 and releasing on August 4th! It’s about two mystery fossils. The first is named Diskagma, which means disc-shaped fragment, and it was only described in 2013. That’s partly because it’s so small, barely two millimeters long at most, and partly because of where it’s found. That would be fossilized in extremely old rocks. When I saw the illustration accompanying the blog post where I learned about Diskagma, I thought it was a cluster of cup-like flowers, sort of like the flowers of the plant called little brown jug. I was ready to send the link to Meredith Hemphill of the Herbarium of the Bizarre podcast, which by the way you should be listening to. But then I saw how old Diskagma is. It’s been dated to 2.2 billion years old. That’s older than any plant, probably by as much as a billion years. Even more astounding, it lived on land. As a reminder, the Cambrian explosion took place about half a billion years ago, when tiny marine animals diversified rapidly to fill new ecological niches. That happened in the water, though, mainly in shallow, warm oceans. If you go back to around 850 million years ago, that may have been roughly the time that land plants evolved from green algae that lived in fresh water. Plant-like algae, or possibly algae-like plants, might be as old as 1 billion years old. But before then, scientists don’t find evidence of anything except microbes living on land, and they were probably restricted to lakes and other bodies of fresh water. That’s because there wasn’t much soil, just broken-up rock that contained very few nutrients and couldn’t retain much water. Diskagma was shaped like a tiny elongated cup, or an urn or vase, with what looks like a stem on one end and what looks like an opening at the other end. The opening contained structures that look like little filaments, but the filaments didn’t fill the whole cup. Most of the cup was diskagma’s body, so to speak, although we don’t know what it contained. We also don’t know what the filaments were for. We do know that the stem actually did connect diskagma to other cups, so that they lived in little groups. We don’t know if it was a single animal with multiple cuplike structures or if it was a colony, or really anything. That’s the problem. We don’t know anything about diskagma except that it existed, and that it lived on land 2.2 billion years ago. Tiny as it was, though, it wasn’t microscopic, and it definitely appears more complex than would be expected that long ago, especially from something living on dry land. One suggestion is that the main part of its body contained a symbiotic bacteria that could convert chemicals to nutrients. As in many modern animals, especially extremophiles, the bacteria would have had a safe place to live and the diskagma would have had nutrients that allowed it to live without needing to eat. Diskagma lived at an interesting time in the earth’s history, called the great oxygenation event, also called the great oxidation event. We talked about it in episode 341 in conjunction with cyanobacteria, because cyanobacteria basically started the great oxygenation event. Cyanobacteria are still around, by the way, and are doing just fine. They’re usually called blue-green algae even though they’re not actually algae. Cyanobacteria photosynthesize,
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    10 min
  • The Books Have Been Claimed! and a bonus mouse
    Jul 28 2025
    I just wanted everyone to know that a listener has claimed the books and magazines I offered for giveaway in episode 443. You can also learn about 60 seconds' worth of information about the African pygmy mouse. The tiniest mouse [photo by Alouise Lynch - Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=59068329]:
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    1 min
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