Megalneusaurus rex

Megalneusaurus is a genus of large pliosaurid plesiosaur from the Late Jurassic of North America. It was provisionally described as a species of Cimoliosaurus by the geologist Wilbur Clinton Knight in 1895, before being given its own genus by the same author in 1898. The only known species is M. rex, known from several specimens mainly found in the Redwater Shale Member, within the Sundance Formation, Wyoming, United States. A specimen discovered in the Naknek Formation in southern Alaska was referred to the genus in 1994. The loss of most fossils has led some paleontologists to consider the genus as dubious, although its validity is maintained by many authors. The binominal name literally means "king of large swimming lizards", due to the size of the first specimen.

Megalneusaurus rex

W. C. Knight · Public Domain · 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
MegalneusaurusPBDB
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 6.7 million years on record.

The one occurrence read is dated to somewhere between 161.5 Mya and 154.8 Mya, which is a dating window rather than a span.

Middle Jurassic — about 0 of 1 occurrenceLate Jurassic — about 1 of 1 occurrenceLate Jurassic162–161 Mya — about 0.0 occurrences161–161 Mya — about 0.0 occurrences161–161 Mya — about 0.0 occurrences161–161 Mya — about 0.0 occurrences161–160 Mya — about 0.0 occurrences160–160 Mya — about 0.0 occurrences160–160 Mya — about 0.0 occurrences160–160 Mya — about 0.0 occurrences160–159 Mya — about 0.0 occurrences159–159 Mya — about 0.0 occurrences159–159 Mya — about 0.0 occurrences159–159 Mya — about 0.0 occurrences159–158 Mya — about 0.0 occurrences158–158 Mya — about 0.0 occurrences158–158 Mya — about 0.0 occurrences158–158 Mya — about 0.0 occurrences158–157 Mya — about 0.0 occurrences157–157 Mya — about 0.0 occurrences157–157 Mya — about 0.0 occurrences157–157 Mya — about 0.0 occurrences157–156 Mya — about 0.0 occurrences156–156 Mya — about 0.0 occurrences156–156 Mya — about 0.0 occurrences156–156 Mya — about 0.0 occurrences156–155 Mya — about 0.0 occurrences155–155 Mya — about 0.0 occurrences155–155 Mya — about 0.0 occurrences155–155 Mya — about 0.0 occurrences162 Mya154.3 Mya

1 occurrence of Megalneusaurus rex on record, most of them in the Late Jurassic. 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

1 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

Sundance — 42.84°N, 107.65°W

Loading coastlines…

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

Megalneusaurus rex and its relatives

Late Jurassic

Where Megalneusaurus rex and its relatives were recorded in the Late Jurassic.

Found in the same rock

No other named taxon is catalogued from that site.

The Paleobiology Database records 1 site for Megalneusaurus rex, and this reads all of them.

Entered from

1 reference

Each of the 1 occurrence 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 the Paleobiology Database's own record for the work.

Media and terms

Media content1

Picture of Megalneusaurus rex

Credit
W. C. Knight
Licence
Public Domain
Commercial use
the licence allows it

No 3D scan of Megalneusaurus rex 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 itMegalneusaurus through timeFormations of the Late JurassicThe world it lived on

Occurrence data from the Paleobiology Database, CC BY 4.0. (Knight 1895)