Meridensia

Meridensia is an extinct genus of prehistoric ray-finned fish that lived during the Anisian and Ladinian ages of the Middle Triassic epoch in what is now southern Switzerland and northern Italy. Fossils were recovered from the Besano Formation of Monte San Giorgio and Besano area at the Swiss-Italian boundary.

Meridensia

Ghedoghedo · CC BY-SA 3.0 · via Wikipedia/Commons. May be a photograph of a specimen, or an artist’s reconstruction — an interpretation of a skeleton, since colour and soft tissue are almost never preserved.

On record

Recorded, not inferred
Sits inside
PerleididaePBDB
Diet
grazer, detritivorePBDB, for Perleididae
Motility
actively mobilePBDB, for Osteichthyes

Time the record covers

At most 4 million years on record.

Every occurrence read is dated to somewhere between 243.43 Mya and 239.48 Mya, and nothing in the dating separates them, so that window is what the record shows rather than a span.

Middle Triassic — about 15 of 15 occurrencesMiddle Triassic243–243 Mya — about 1 occurrence243–243 Mya — about 1 occurrence243–243 Mya — about 1 occurrence243–243 Mya — about 1 occurrence243–243 Mya — about 1 occurrence243–242 Mya — about 1 occurrence242–242 Mya — about 1 occurrence242–242 Mya — about 1 occurrence242–242 Mya — about 1 occurrence242–242 Mya — about 1 occurrence242–242 Mya — about 1 occurrence242–241 Mya — about 1 occurrence241–241 Mya — about 0.0 occurrences241–241 Mya — about 0.0 occurrences241–241 Mya — about 0.0 occurrences241–241 Mya — about 0.0 occurrences241–241 Mya — about 0.0 occurrences241–240 Mya — about 0.0 occurrences240–240 Mya — about 0.0 occurrences240–240 Mya — about 0.0 occurrences240–240 Mya — about 0.0 occurrences240–240 Mya — about 0.0 occurrences240–240 Mya — about 0.0 occurrences240–239 Mya — about 0.0 occurrences243.93 Mya238.98 Mya

15 occurrences of Meridensia on record, most of them in the Middle Triassic. Bar height is expected occurrences, not a count: each fossil is spread across the span it is dated to, so a tall narrow bar means tight dating and a low wide one means loose.

When

15 occurrences

These are dates about fossils, not the animal: the record can only begin after it arose and end before it died out, so either end may reach further. Shares are expected occurrences: a fossil dated to a span is counted partly in each period it straddles. More on what this infers.

Found in

2 formations

Besano — 45.91°N, 8.95°EBesano — 45.90°N, 8.96°EBesano — 45.89°N, 8.90°EBesano — 45.96°N, 8.81°E

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The named rock units Meridensia has been recovered from, largest first. Drawn where the rock is now, not where it formed.

Meridensia and its relatives

Middle Triassic

Where Meridensia and its relatives were recorded in the Middle Triassic.

Found in the same rock

90 taxa

The Paleobiology Database records 14 sites for Meridensia, and this reads all of them. The number is how many of those sites it was catalogued from too. The 24 sharing the most are listed.

This is not a list of everything alive at the time. It is only what has come out of the same ground as this animal and been written down.

Entered from

5 references

Each of the 15 occurrences read was entered from one of these publications, ordered by how many each accounts for. This is not a search for papers mentioning the name. Entries link to doi.org where the Paleobiology Database holds an identifier, and to its own record where it does not. Relayed as the Paleobiology Database holds them, not checked against what they resolve to.

Media and terms

Media content1

Picture of Meridensia

Credit
Ghedoghedo
Licence
CC BY-SA 3.0
Commercial use
the licence allows it

No 3D scan of Meridensia was found in MorphoSource and Sketchfab.

Smithsonian Open Access was not reached for this taxon, so this list is what the others held rather than everything there is.

The description on this site

Licence
CC BY-SA 4.0

This is what the site found, which is not the same as what exists.

Keep going

What may have been alongside itPerleididae through timeFormations of the Middle TriassicThe world it lived on

Occurrence data from the Paleobiology Database, CC BY 4.0. Andersson 1916