Dryolestidae

Dryolestidae is an extinct family of Mesozoic mammals, known from the Middle Jurassic to the Early Cretaceous of the North Hemisphere. The oldest known member, Anthracolestes, is known from the Middle Jurassic Itat Formation of Western Siberia, but most other representatives are known from the Late Jurassic of North America and the Late Jurassic and Early Cretaceous of Europe. Most members are only known from isolated teeth and jaw fragments. Like many other groups of early mammals, they are thought to have been insectivores. They are generally classified in Cladotheria, meaning that they are considered to be more closely related to marsupials and placentals than to monotremes. They are placed as part of the broader Dryolestida, which also includes the Paurodontidae, and also sometimes the South American-Antarctic Meridiolestida, which are often considered unrelated cladotherians. Dryolestidae taxon is not based on a phylogenetic definition, but instead on the possession of unequal roots for the molars of the lower jaw. Additionally, the clade is distinguished by hypsodonty in lower molars, and uneven labio-lingual height for the alveolar borders of the dentary.

Dryolestidae

Othniel Charles Marsh · 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
DryolestoideaPBDB
Diet
insectivorePBDB, for Mammaliaformes
Life habit
scansorialPBDB, for Mammaliaformes
Motility
actively mobilePBDB, for Osteichthyes
Environment
terrestrialPBDB, for Mammalia

Time the record covers

At least 93 million years on record.

The record covers at least 165.3 Mya to 72.2 Mya. No occurrence read is dated outside 168.2 Mya to 66 Mya.

Middle Jurassic — about 2 of 100 occurrencesMiddle JurassicLate Jurassic — about 66 of 100 occurrencesLate JurassicEarly Cretaceous — about 24 of 100 occurrencesEarly CretaceousLate Cretaceous — about 8 of 100 occurrencesLate CretaceousPaleocene — about 0 of 100 occurrences170–167 Mya — about 1 occurrence167–163 Mya — about 1.0 occurrences156–153 Mya — about 9 occurrences153–149 Mya — about 19 occurrences149–145 Mya — about 23 occurrences145–142 Mya — about 17 occurrences142–138 Mya — about 15 occurrences138–135 Mya — about 2 occurrences135–131 Mya — about 2 occurrences131–128 Mya — about 0.2 occurrences128–124 Mya — about 0.7 occurrences124–121 Mya — about 1 occurrence121–117 Mya — about 0.3 occurrences85–82 Mya — about 0.3 occurrences82–78 Mya — about 0.6 occurrences78–75 Mya — about 0.6 occurrences75–71 Mya — about 2 occurrences71–67 Mya — about 3 occurrences67–64 Mya — about 1 occurrence165.3 Mya72.2 Mya170 Mya64 Mya

100 occurrences of Dryolestidae 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

100 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

14 formations

Morrison — 38.54°N, 105.22°WMorrison — 41.89°N, 106.00°WMorrison — 41.99°N, 106.08°WMorrison — 40.47°N, 109.18°WMorrison — 39.15°N, 108.77°WMorrison — 38.99°N, 109.27°WMorrison — 44.46°N, 104.73°WMorrison — 44.02°N, 104.24°WLulworth — 50.60°N, 1.97°WAlcobaça — 39.70°N, 8.80°WKsar Metlili — 32.70°N, 3.22°WLourinhã — 39.22°N, 9.34°WLos Alamitos — 41.95°S, 66.33°WAllen — 39.78°S, 66.70°WWadhurst Clay — 50.89°N, 0.69°EWadhurst Clay — 51.01°N, 0.76°ELakota — 43.32°N, 103.62°WLakota — 44.20°N, 103.33°WMesaverde — 44.12°N, 107.76°WForest Marble — 51.87°N, 1.27°WItat — 55.65°N, 89.18°EEl Molino — 17.69°S, 65.94°WAnacleto — 39.12°S, 67.67°W

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The named rock units Dryolestidae has been recovered from, largest first. Drawn where the rock is now, not where it formed. 4 occurrences have no formation on record, which is common for older literature.

Dryolestidae and its relatives

Late Jurassic

Where Dryolestidae and its relatives were recorded in the Late Jurassic.

Found in the same rock

640 taxa

The Paleobiology Database records 38 sites for Dryolestidae, 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

44 references

Each of the 100 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. 32 further references are not listed. 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 Dryolestidae

Credit
Othniel Charles Marsh
Licence
Public Domain
Commercial use
the licence allows it

No 3D scan of Dryolestidae 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 itDryolestoidea through timeFormations of the Late JurassicThe world it lived on

Occurrence data from the Paleobiology Database, CC BY 4.0. Marsh 1879