Helodermatidae

The Helodermatidae or beaded lizards are a small family of lizards endemic to North America today, mainly found in the Isthmus of Tehuantepec in Oaxaca, the central lowlands of Chiapas, on the border of Guatemala, and in the Nentón River Valley, though they were formerly more widespread in the ancient past. Traditionally, the Gila monster and the Mexican beaded lizard were the only species recognized, although the latter has recently been split into several species.

Helodermatidae

Josh Olander · CC BY 4.0 · 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
VaranoideaPBDB
Diet
carnivorePBDB
Life habit
ground dwellingPBDB
Motility
actively mobilePBDB, for Osteichthyes
Environment
terrestrialPBDB, for Amniota

Time the record covers

At least 42 million years on record.

The record covers at least 72.2 Mya to 29.5 Mya. No occurrence read is dated outside 83.6 Mya to 18.5 Mya.

Late Cretaceous — about 16 of 27 occurrencesLate CretaceousPaleocene — about 0 of 27 occurrencesEocene — about 7 of 27 occurrencesEoceneOligocene — about 4 of 27 occurrencesOligoceneMiocene — about 0 of 27 occurrencesMiocene85–83 Mya — about 1 occurrence83–80 Mya — about 3 occurrences80–78 Mya — about 3 occurrences78–76 Mya — about 3 occurrences76–74 Mya — about 3 occurrences74–71 Mya — about 2 occurrences58–56 Mya — about 0.4 occurrences56–53 Mya — about 2 occurrences53–51 Mya — about 2 occurrences51–49 Mya — about 1 occurrence49–47 Mya — about 0.5 occurrences42–40 Mya — about 0.4 occurrences40–38 Mya — about 0.6 occurrences35–33 Mya — about 0.4 occurrences33–31 Mya — about 1 occurrence31–28 Mya — about 1 occurrence28–26 Mya — about 0.7 occurrences26–24 Mya — about 0.2 occurrences24–22 Mya — about 0.2 occurrences22–19 Mya — about 0.2 occurrences19–17 Mya — about 0.1 occurrences72.2 Mya29.5 Mya85 Mya17 Mya

27 occurrences of Helodermatidae on record, most of them in the Late Cretaceous. The Paleobiology Database records this as a living group, and the chart stops with its fossils rather than at the present. 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

27 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

6 formations

Oldman — 49.10°N, 110.94°WOldman — 49.08°N, 110.84°WOldman — 49.08°N, 110.68°WOldman — 49.16°N, 110.72°WOldman — 50.70°N, 111.50°WForemost — 50.07°N, 111.14°WForemost — 49.13°N, 110.87°WTienen — 50.82°N, 5.10°ELignites de Soissonais — 49.05°N, 4.00°EWasatch — 41.70°N, 109.00°WWilliams Fork — 39.93°N, 108.82°W

Loading coastlines…

The named rock units Helodermatidae has been recovered from, largest first. Drawn where the rock is now, not where it formed. 8 occurrences have no formation on record, which is common for older literature.

Helodermatidae and its relatives

Late Cretaceous

Where Helodermatidae and its relatives were recorded in the Late Cretaceous.

Found in the same rock

505 taxa

The Paleobiology Database records 26 sites for Helodermatidae, 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

8 references

Each of the 27 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 Helodermatidae

Credit
Josh Olander
Licence
CC BY 4.0
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 itVaranoidea through timeFormations of the Late CretaceousThe world it lived on

Occurrence data from the Paleobiology Database, CC BY 4.0. Gray 1837