Umoonasaurus demoscyllus

Umoonasaurus is an extinct genus of plesiosaur belonging to the family Leptocleididae. This genus lived approximately 115 million years ago during the Early Cretaceous period, in shallow seas covering parts of what is now Australia. It was a relatively small animal around 2.5 metres (8.2 ft) long. An identifying trait of Umoonasaurus is the presence of three crest-ridges on its skull.

Umoonasaurus demoscyllus

Geekgecko · CC0 · 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
UmoonasaurusPBDB
Diet
carnivorePBDB, for Plesiosauria
Life habit
aquatic, depth=surfacePBDB, for Plesiosauria
Motility
actively mobilePBDB, for Plesiosauria
Environment
marinePBDB, for Plesiosauria

Time the record covers

At most 21 million years on record.

Every occurrence read is dated to somewhere between 121.4 Mya and 100.5 Mya, and nothing in the dating separates them, so that window is what the record shows rather than a span.

Early Cretaceous — about 4 of 4 occurrencesEarly CretaceousLate Cretaceous — about 0 of 4 occurrences122–121 Mya — about 0.0 occurrences121–120 Mya — about 0.1 occurrences120–120 Mya — about 0.1 occurrences120–119 Mya — about 0.2 occurrences119–118 Mya — about 0.2 occurrences118–118 Mya — about 0.2 occurrences118–117 Mya — about 0.2 occurrences117–116 Mya — about 0.2 occurrences116–115 Mya — about 0.2 occurrences115–115 Mya — about 0.2 occurrences115–114 Mya — about 0.2 occurrences114–113 Mya — about 0.2 occurrences113–112 Mya — about 0.1 occurrences112–112 Mya — about 0.1 occurrences112–111 Mya — about 0.1 occurrences111–110 Mya — about 0.1 occurrences110–109 Mya — about 0.1 occurrences109–109 Mya — about 0.1 occurrences109–108 Mya — about 0.1 occurrences108–107 Mya — about 0.1 occurrences107–107 Mya — about 0.1 occurrences107–106 Mya — about 0.1 occurrences106–105 Mya — about 0.1 occurrences105–104 Mya — about 0.1 occurrences104–104 Mya — about 0.1 occurrences104–103 Mya — about 0.1 occurrences103–102 Mya — about 0.1 occurrences102–101 Mya — about 0.1 occurrences101–101 Mya — about 0.1 occurrences101–100 Mya — about 0.0 occurrences121.9 Mya100 Mya

4 occurrences of Umoonasaurus demoscyllus on record, most of them in the Early Cretaceous. 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

4 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

1 formation

Bulldog Shale — 29.01°S, 134.67°EBulldog Shale — 29.30°S, 137.42°EBulldog Shale — 27.85°S, 135.92°EBulldog Shale — 30.45°S, 137.17°E

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

Umoonasaurus demoscyllus and its relatives

Early Cretaceous

Where Umoonasaurus demoscyllus and its relatives were recorded in the Early Cretaceous.

Found in the same rock

2 taxa

The Paleobiology Database records 4 sites for Umoonasaurus demoscyllus, and this reads all of them. The number is how many of those sites it was catalogued from too.

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

1 reference

Each of the 4 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. Each entry links to doi.org. Relayed as the Paleobiology Database holds them, not checked against what they resolve to.

Media and terms

Media content1

Picture of Umoonasaurus demoscyllus

Credit
Geekgecko
Licence
CC0
Commercial use
the licence allows it

No 3D scan of Umoonasaurus demoscyllus was found in Sketchfab.

Smithsonian Open Access and MorphoSource were 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 itUmoonasaurus through timeFormations of the Early CretaceousThe world it lived on

Occurrence data from the Paleobiology Database, CC BY 4.0. Kear et al. 2006