Pterygolepis is an extinct genus of jawless fish from the Silurian period. Known for its distinct scale-like body covering and unique fin structure, Pterygolepis provides valuable insights into the diversity and adaptation of early vertebrates.
Taxonomy and Classification
Kingdom: Animalia
Phylum: Chordata
Class: Anaspida
Order: Pharyngolepiformes
Family: Pharyngolepididae
Geological Time & Habitat
Geological Time Period: Silurian (approximately 430 million years ago)
Typical Environment: Pterygolepis thrived in shallow marine environments, likely inhabiting coastal areas rich in food resources.
Discovery & Classification
Date: Early 20th century
Discovery Location: Estonia
Discovering Paleontologist(s): Gunnar Säve-Söderbergh
The genus Pterygolepis was described based on well-preserved fossils found in Estonia, significantly contributing to our understanding of early vertebrate morphology and ecology.
Physical Characteristics
Size and Weight: Pterygolepis was a small fish, typically around 15 centimetres in length.
Unique Features: It had a robust body covered with distinct scale-like structures and a unique fin structure. Its body plan can be loosely compared to modern fish in terms of shape and size, though it was jawless.
Synapomorphies
Pterygolepis had a hypocercal tail, where the vertebrae extended downward into the lower lobe, which was more developed than the upper lobe. It also had unique body fins along the entire sides of its body, which are not homologous with the fins seen on modern fish. All members of the class Anaspida are vertebrates but true agnathians on the Cyclostome line of the vertebrate tree, meaning they are more closely related to hagfishes, lampreys, and conodonts than to today’s fish.
Known Species
Pterygolepis nitida
Behaviour & Ecology
Diet: Likely a filter feeder, consuming small particles and microorganisms from the water.
Behaviour: Pterygolepis was probably an active swimmer, using its tail for manoeuvring in its shallow marine habitat.
Ecological Interactions: Coexisted with other early vertebrates and a variety of invertebrates, contributing to the complex ecosystems of the Silurian seas.
Fossil Discoveries
Significant Discoveries Timeline: Early 20th century: First described by Gunnar Säve-Söderbergh.
Key Paleontologists: Gunnar Säve-Söderbergh, Erik Stensiö
Fossil Sites: Estonia; Silurian rock formations in Gotland, Sweden. These sites are crucial for studying the diversity of Silurian vertebrates.
Current Specimen Locations
Natural History Museum, Tallinn
Swedish Museum of Natural History.
These institutions house some of the most complete and well-preserved specimens.
Scientific Research & Theories
Recent Studies: Focus on the anatomical adaptations and phylogenetic relationships of Pterygolepis within the anaspids and early vertebrates.
Scientific Debates: Ongoing discussions about the evolutionary significance of Pterygolepis and its relationship with other jawless fish.
Extinction Theories
Theories and Debates: Pterygolepis and other anaspids faced extinction towards the end of the Silurian period, likely due to changing environmental conditions and increased competition with emerging jawed vertebrates.
Cultural & Historical Impact
Pop Culture and Media: Pterygolepis has not been widely featured in popular media but is occasionally mentioned in scientific literature and documentaries about early vertebrate evolution.
Pop Culture Influence: The genus remains largely unknown outside of scientific communities.
Interesting Facts & Trivia
Distinctive Scales: Pterygolepis’ scale-like body covering is unique among early vertebrates, indicating a specialized form of protection and adaptation.
Discover More Fascinating Anaspids
Pterygolepis has some famous cousins like Birkenia, Pharyngolepis, Lasanius and Rhyncholepis (previously known as Anaspis, the genera that gave Anaspids their name but has since fallen away).
Other extremely interesting Anaspida are the Canadian discovery with the insanely large hypocercal tail, Endeiolepis and Scotland’s spiny-backed Cowielepis and Devonian kerreralepis.
Documentaries Featuring Some Awesome Early Vertebrates Like Pterygolepis
They’re not always 100% accurate because we make new scientific discoveries all the time. But documentaries at least deliver the gist of the information in a fun and engaging way. Just click play, hit full screen and enjoy hours’ worth of awesome documentaries on first animals, right here…
1. Ancient Oceans
2019
Not just about vertebrates, but featuring some of the most awesome ancient fishes. This short documentary about early oceans and extinction events has two episodes and is available through Curiosity Stream here.
2. Animal Armageddon Episode 2
Animal Planet, 2019
It’s hard to track down a good copy of this one, but Animal Armageddon features quite a few vertebrate evolutionary stories, pegged on the major mass extinctions they faced. This one specifically is during the Devonian, the age of fishes (vertebrates).
Also available on Amazon here.
3. Mankind Rising
2012
The 2012 TV movie production of Mankind Rising is a single animated journey from the earliest vertebrates ancestors right through to present-day humans – it’s pretty cool, maybe a bit dated, but still a lot of fun!
4. Walking with Monsters
BBC, 2005
A bit older now and flashing past early animals a bit too quickly, this one in the “Walking With” series is still pretty cool for its Cambrian bits. It’s also available via Amazon.
5. David Attenborough’s Rise of Animals: Triumph of the Vertebrates
BBC, 2013
Although more focused on the evolution of vertebrates, it’s still an awesome documentary to watch. It’s available to purchase from Amazon.
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Enjoy the journey of discovery through Earth’s ancient past, geology, big ideas and, of course, awesome prehistoric life.
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