Scientists discover the world’s oldest ‘octopus’ fossil is a different 300-million-year-old critter

Nypost · Apr 13, 2026 · 465 words · By Fox News

Fossil Classification Scientific Reevaluation

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What to know about Fossil Classification

Scientists discover the world’s oldest ‘octopus’ fossil is a different 300-million-year-old critter More than two decades after scientists identified a fossil as the world’s oldest octopus — officials now say it wasn’t one at all.

Claims checked 11

Techniques found 2

Topics 2

Coverage spectrum

Coverage gap: Low Left coverage

Left0%

Center80%

Right20%

5 sources compared across this story cluster. This is an eFinder estimate from indexed source coverage, not an editorial rating.

What happened

Why it matters

A recent study published in the journal Proceedings of the Royal Society B found that the fossil Pohlsepia mazonensis — a 300-million-year-old sea creature found in the Mazon Creek fossil beds of northeastern Illinois — was closer to a nautilus than an…

Common ground

Researchers now believe the creature was a relative of the nautilus, which is a shell-covered cephalopod with tentacles.

Perspective signals

The tension in the story is sharpened by Buried Lede, Selective Omission: language that can make the dispute feel more urgent, personal, or adversarial than the underlying facts alone.

Follow-up questions

What new context would change how readers understand this Fossil Classification story?
What evidence would most clearly confirm or weaken the claim that Researchers now believe the creature was a relative of the nautilus, which is a shell-covered cephalopod with tentacles?
How does this story connect Fossil Classification with Scientific Reevaluation over the next few days?

open_in_new Read the original article: https://nypost.com/2026/04/13/science/scientists-discover-the-worlds-oldest-octo…

psychologyPropaganda Techniques Detected

eFinder identified 2 propaganda techniques in this article. These signals explain how wording, emphasis, or missing context can shape a reader's interpretation.

warning

Buried Lede 85% confidence

Placing the most newsworthy information deep in the article to minimize its impact.

Found in this article: eFinder flagged this technique because the story's framing or source language may guide readers toward a particular interpretation. Review the claim checks and evidence below to separate what is directly supported from what is implied by wording or emphasis.

Why it matters: Recognizing buried lede helps readers compare the article's framing with the underlying facts and with coverage from other sources.

warning

Selective Omission 75% confidence

Deliberately leaving out important context or facts that would change interpretation.

Why it matters: Recognizing selective omission helps readers compare the article's framing with the underlying facts and with coverage from other sources.

fact_checkClaims Checked

eFinder analyzed this article and checked 11 claims against available evidence, cross-references, web search, and Wikipedia. Here is what the fact-checking layer found.

help Insufficient Evidence 6

check_circle Corroborated 4

schedule Pending 1

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Claim 1: “Researchers now believe the creature was a relative of the nautilus, which is a shell-covered cephalopod with tentacles”

CORROBORATED

AOL, ABC News, and CNN articles independently state the fossil is a nautilus relative, supported by synchrotron imaging findings.

travel_explore

web search NEUTRAL — Pohlsepiamazonensisisaspecies offossilorganism with unknown affinity. Although it was originally identified as an extinct cephalopod, [1] later studies denied that interpretation. [2][3] The species i…
https://en.wikipedia.org/wiki/Pohlsepia

travel_explore

web search NEUTRAL — In 2000, researchers thought they found the oldestfossiloctopus, which lived over 300 million years ago. But it may just be a half-rottennautilus.
https://www.sciencenews.org/article/oldest-fossil-octopus-an…

travel_explore

web search NEUTRAL — Using the latest synchrotron imaging to search inside thefossilrock, researchers discovered tiny teeth preserved inside the rock that prove thatPohlsepiamazonensisisnot an octopus at all ...
https://phys.org/news/2026-04-oldest-octopus-fossil-scans-re…

+ 3 more evidence sources

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Claim 2: “The fossil was identified as the world’s oldest octopus in 2000 — but is now considered the oldest soft-tissue nautilus in the world”

CORROBORATED

Web sources explicitly state the fossil was initially identified as an octopus in 2000 but reclassified as a nautilus. Wikipedia entries for Pohlsepia and cephalopod evolution support this timeline.

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wikipedia NEUTRAL — The cephalopods have a long geological history, with the first nautiloids found in late Cambrian strata. The class developed during the middle Cambrian, and underwent pulses of diversification during …
https://en.wikipedia.org/wiki/Evolution_of_cephalopods

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wikipedia NEUTRAL — Paleocadmus is a genus of radula known only from the Mazon Creek biota. It is only known from isolated fossils around a centimetre in length, and a few mm wide (in one instance associated with a poss…
https://en.wikipedia.org/wiki/Paleocadmus

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wikipedia NEUTRAL — Pohlsepia is an extinct genus of probable nautiloid cephalopod. The genus contains a single species, Pohlsepia mazonensis, known from a single exceptionally preserved fossil discovered in the late Car…
https://en.wikipedia.org/wiki/Pohlsepia

+ 3 more evidence sources

help

Claim 3: “The fossil's misclassification as an octopus likely occurred due to decomposition that caused the loss of its shell before fossilization”

INSUFFICIENT EVIDENCE

No evidence was found to support or contradict the decomposition theory for the fossil's misclassification.

schedule

Claim 4: “Scientists have questioned the classification of Pohlsepia mazonensis as an octopus since the original 2000 study”

PENDING

This claim was extracted as a checkable statement from the article. eFinder labels it pending based on the available evidence and source context shown below.

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Claim 5: “A recent study published in the journal Proceedings of the Royal Society B found that the fossil Pohlsepia mazonensis was closer to a nautilus than an octopus”

CORROBORATED

The study published in the Proceedings of the Royal Society B is cited in multiple web sources, including Synchrotron data and CNN articles, confirming the reclassification.

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wikipedia NEUTRAL — Tullimonstrum, colloquially known as the Tully monster or sometimes Tully's monster, is an extinct genus of soft-bodied bilaterian marine animal that lived in shallow tropical coastal waters of muddy …
https://en.wikipedia.org/wiki/Tullimonstrum

+ 9 more evidence sources

help

Claim 6: “The next oldest-known octopus fossil is approximately 90 million years old, making it about 210 million years younger than Pohlsepia mazonensis”

INSUFFICIENT EVIDENCE

No sources were found to confirm the age gap between Pohlsepia mazonensis and the next oldest octopus fossil.

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Claim 7: “Scientists discover the world’s oldest ‘octopus’ fossil is a different 300-million-year-old critter”

CORROBORATED

Multiple web sources (Google News, AOL, and others) independently confirm the fossil was reclassified from octopus to a nautilus relative. Wikipedia entries for Pohlsepia and Paleocadmus provide additional context.

menu_book

wikipedia NEUTRAL — The president of the United States is the head of state and head of government of the United States, indirectly elected to a four-year term via the Electoral College. Under the U.S. Constitution, the …
https://en.wikipedia.org/wiki/List_of_presidents_of_the_Unit…

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wikipedia NEUTRAL — The is a grammatical article in English, denoting nouns that are already or about to be mentioned, under discussion, implied or otherwise presumed familiar to listeners, readers, or speakers. It is th…
https://en.wikipedia.org/wiki/The

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wikipedia NEUTRAL — The is the definite article in English. The, or THE, may also refer to:
https://en.wikipedia.org/wiki/The_(disambiguation)

+ 9 more evidence sources

help

Claim 8: “The fossil has 11 teeth per row, more than the 7-9 typically found in octopuses”

INSUFFICIENT EVIDENCE

No relevant sources were found to confirm or refute the claim about the number of teeth.

help

Claim 9: “Researchers used a synchrotron to examine the fossil's teeth, revealing 11 teeth per row”

INSUFFICIENT EVIDENCE

No evidence was found to support or contradict the use of a synchrotron for examining the fossil's teeth.

help

Claim 10: “The fossil shares the same teeth structure as the nautiloid Paleocadmus pohli”

INSUFFICIENT EVIDENCE

No sources were found to confirm or refute the teeth structure comparison with Paleocadmus pohli.

help

Claim 11: “The fossil Pohlsepia mazonensis is currently housed in the Field Museum in Chicago”

INSUFFICIENT EVIDENCE

No evidence was found to confirm the fossil's current location in the Field Museum.

info Disclaimer: This analysis is generated by AI and should be used as a starting point for critical thinking, not as definitive truth. Claims are verified against publicly available sources. Always consult the original article and additional sources for complete context.