Fish
Physonemus altonensis
Physonemus altonensisAlso known as Anvil Shark, Ironing Board Shark
Stethacanthus altonensis navigated warm, shallow Carboniferous seas using specialized pelvic claspers and a streamlined cartilaginous body. Mature males displayed a bizarre dorsal fin spine resembling an anvil or ironing board, capped with a dense patch of enlarged denticles that mirrored a matching brush on the top of the skull. Paleontologists suspect this ornate crest functioned in courtship display, species recognition, or perhaps as an intimidating false mouth to deter larger predators.
PrehistoricMarine
—observations
—countries
—peak records
ExtinctConservation statusIUCN Red List categoriesLCNTVUENCREWEXExtinctRed List categories, explained →
Diet & preySmall palaeoniscoid fish, Ammonoids, Benthic crustaceans
Predators
- Large placoderms
- Edestus
- Rhizodonts
ThreatsLate Paleozoic environmental shifts and marine turnover
HabitatsShallow epicontinental seas and coastal marine waters
Life span10–20 years
Classification
- FamilyStethacanthidae
- SpeciesPhysonemus altonensis
Range data is not available yet.
Interaction riskLow
- Low
- Moderate
- High
- Very high
- Why interaction risk is low
- Extinct prehistoric species known only from fossil deposits.
Responsible observation
- Museum Viewing: Examine articulated skeletal impressions preserved in fine-grained marine limestones.
- Fossil Identification: Look for the telltale brush of denticles atop the flattened dorsal spine plate.
Neighbor Slate Weasel / CC BY 4.0 · cc-by
Close Relative Tommy from Arad / CC BY 2.0 · cc-by
Close Relative https://www.si.edu/object/akmonistion-zangerli-coates-sequeira:nmnhpaleobiology_3421162 / CC BY-SA 4.0 · cc-by-sa
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