Pharyngolepis is an extinct genus of jawless fish from the early Silurian period. Known for its elongated body and unique skeletal features, Pharyngolepis provides important 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: Pharyngolepis inhabited shallow marine environments, likely favouring coastal areas with abundant food resources.
Discovery & Classification
Date: Early 20th century.
Discovery Location: Norway
Discovering Paleontologist(s): Otto M. Torell
The genus Pharyngolepis was described based on well-preserved fossils found in Norway, contributing significantly to our understanding of early vertebrate morphology.
Physical Characteristics
Size and Weight: Pharyngolepis was a moderately sized fish, generally around 15-20 centimetres in length.
Unique Features: It possessed an elongated body with a series of dorsal and ventral fin folds. Unlike many other anaspids, it had a relatively simple head structure without extensive bony armour. Its body plan can be somewhat compared to modern eels in terms of elongation and swimming style.
Synapomorphies
Pharyngolepis had a hypocercal tail, where the lower lobe is 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
Pharyngolepis oblongus
Behaviour & Ecology
Diet: Likely a detritivore or filter feeder, consuming small particles from the water or substrate.
Behaviour: Pharyngolepis was probably a slow-moving swimmer, using its body undulations to navigate its environment.
Ecological Interactions: Coexisted with other early vertebrates and various marine invertebrates, contributing to the complex ecosystems of the Silurian seas.
Fossil Discoveries
Significant Discoveries Timeline: Early 20th century: First described by Otto M. Torell.
Key Paleontologists: Otto M. Torell, Erik Stensiö
Fossil Sites: Norway; Ringerike Group, Scotland. These sites are crucial for studying the diversity of Silurian vertebrates.
Current Specimen Locations
Natural History Museum, Oslo
National Museum of Scotland.
These institutions hold some of the most complete and informative specimens.
Scientific Research & Theories
Recent Studies: Focus on the anatomy and phylogenetic relationships of Pharyngolepis within the anaspids and early vertebrates.
Scientific Debates: Discussions continue regarding the evolutionary pathways and ecological niches occupied by Pharyngolepis and related genera.
Extinction Theories
Theories and Debates: Pharyngolepis and other anaspids faced extinction towards the end of the Silurian period, likely due to environmental changes and competition with emerging jawed vertebrates.
Cultural & Historical Impact
Pop Culture and Media: Pharyngolepis is rarely featured in popular media but is occasionally mentioned in scientific discussions about early vertebrate evolution.
Pop Culture Influence: The genus remains largely unknown outside of paleontological circles.
Interesting Facts & Trivia
Elongated Body: The body shape of Pharyngolepis is unique among early vertebrates, indicating specialized swimming adaptations.
Simple Head Structure: Its lack of extensive bony armour differentiates it from many other early jawless fish, suggesting a different ecological strategy.
Discover More Fascinating Anaspids
Pharyngolepis has some famous cousins like Birkenia, Lasanius, Pterygolepis 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 the Devonian kerreralepis.
Documentaries Featuring Some Awesome Early Vertebrates Like Pharyngolepis
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. Australia: A Time Traveller’s Guide Episode 2
Richard Smith, 2012
Though not specifically focused on vertebrates, Episode 2 of the charming Australia: A Time Traveller’s Guide (Australia’s First 4 Billion Years) is all about tracking the continent’s record of animals’ invasion of land. Starting off with features of early vertebrate fish Arandaspis to later placoderms and reefs of the Devonian, as well as invertebrate tracks on land in the Silurian.
You can also find it on AppleTV here.
3. 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.
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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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