Amargasaurus cazaui

Amargasaurus is a genus of sauropod dinosaur from the Early Cretaceous epoch of what is now Argentina. The only known skeleton was discovered in 1984 and is virtually complete, including a fragmentary skull, making Amargasaurus one of the best-known sauropods of its epoch. Amargasaurus was first described in 1991 and contains a single known species, Amargasaurus cazaui. It was a large animal, but small for a sauropod, reaching 9 to 13 meters in length. Most distinctively, it sported two parallel rows of tall spines down its neck and back, taller than in any other known sauropod. Several studies postulated that, in life, the spines stuck out of the body as individual structures that supported a horn sheath. Analysis of the bone structure suggests that the spines were connected by ligaments and could have formed a scaffold supporting a neck sail. They might have been used for display, combat, or defense.

Amargasaurus cazaui

Jan Helebrant · 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
AmargasaurusPBDB
Diet
herbivorePBDB, for Sauropoda
Life habit
ground dwelling, gregariousPBDB, for Sauropoda
Motility
actively mobilePBDB, for Sauropoda
Environment
terrestrialPBDB, for Sauropoda

Time the record covers

At most 4.4 million years on record.

Every occurrence read is dated to somewhere between 125.77 Mya and 121.4 Mya, and nothing in the dating separates them, so that window is what the record shows rather than a span.

Early Cretaceous — about 2 of 2 occurrencesEarly Cretaceous126–126 Mya — about 0.0 occurrences126–126 Mya — about 0.1 occurrences126–125 Mya — about 0.1 occurrences125–125 Mya — about 0.1 occurrences125–125 Mya — about 0.1 occurrences125–125 Mya — about 0.1 occurrences125–125 Mya — about 0.1 occurrences125–124 Mya — about 0.1 occurrences124–124 Mya — about 0.1 occurrences124–124 Mya — about 0.1 occurrences124–124 Mya — about 0.1 occurrences124–124 Mya — about 0.1 occurrences124–124 Mya — about 0.1 occurrences124–123 Mya — about 0.1 occurrences123–123 Mya — about 0.1 occurrences123–123 Mya — about 0.1 occurrences123–123 Mya — about 0.1 occurrences123–123 Mya — about 0.1 occurrences123–123 Mya — about 0.1 occurrences123–122 Mya — about 0.1 occurrences122–122 Mya — about 0.1 occurrences122–122 Mya — about 0.1 occurrences122–122 Mya — about 0.1 occurrences122–122 Mya — about 0.1 occurrences122–121 Mya — about 0.1 occurrences121–121 Mya — about 0.0 occurrences126.3 Mya120.9 Mya

2 occurrences of Amargasaurus cazaui 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

2 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

La Amarga — 39.48°S, 70.19°W

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

Amargasaurus cazaui and its relatives

Early Cretaceous

Where Amargasaurus cazaui and its relatives were recorded in the Early Cretaceous.

Found in the same rock

5 taxa

The Paleobiology Database records 2 sites for Amargasaurus cazaui, 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

2 references

Each of the 2 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 Amargasaurus cazaui

Credit
Jan Helebrant
Licence
CC0
Commercial use
the licence allows it

No 3D scan was found. Smithsonian Open Access, MorphoSource and Sketchfab were all searched.

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 itAmargasaurus through timeFormations of the Early CretaceousThe world it lived on

Occurrence data from the Paleobiology Database, CC BY 4.0. Salgado and Bonaparte 1991