Synapsida

Synapsida is a diverse group of tetrapod vertebrates that includes all mammals and their extinct relatives. It is one of the two major clades of the group Amniota, the other being the more diverse group Sauropsida. Synapsids have a single lower temporal fenestra, an opening low in the skull roof behind each eye socket. These openings create a bony arch that allows for the attachment of larger jaw muscles and a more efficient bite. While previously argued to be distinctive to synapsids, single temporal fenestrae are also found in many primitive sauropsids. It has recently been argued that the last common ancestor of synapsids and sauropsids shared a single lower temporal fenestra.

Synapsida

Nobu Tamura Max Bellomio Roman Uchytel Dmitry Bogdanov Fir0002 John and Karen, retouched by Zwoenitzer · 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
Also called
synapsidPBDB
Sits inside
AmniotaPBDB
Motility
actively mobilePBDB, for Osteichthyes
Environment
terrestrialPBDB, for Amniota

Time the record covers

At least 298 million years on record.

The record covers at least 298.9 Mya to 11.7 ka. No occurrence read is dated outside 303.7 Mya to 0 Mya.

Carboniferous — about 3 of 12000 occurrencesPermian — about 4 of 12000 occurrencesPermianEarly Triassic — about 0 of 12000 occurrencesMiddle Triassic — about 1 of 12000 occurrencesLate Triassic — about 4 of 12000 occurrencesLate TriassicEarly Jurassic — about 2 of 12000 occurrencesEarly JurassicMiddle Jurassic — about 0 of 12000 occurrencesLate Jurassic — about 0 of 12000 occurrencesEarly Cretaceous — about 31 of 12000 occurrencesEarly CretaceousLate Cretaceous — about 1294 of 12000 occurrencesLate CretaceousPaleocene — about 4116 of 12000 occurrencesEocene — about 5972 of 12000 occurrencesOligocene — about 37 of 12000 occurrencesMiocene — about 342 of 12000 occurrencesPliocene — about 81 of 12000 occurrencesPleistocene — about 97 of 12000 occurrences310–299 Mya — about 3 occurrences299–289 Mya — about 2 occurrences289–279 Mya — about 0.9 occurrences268–258 Mya — about 1 occurrence248–237 Mya — about 0.9 occurrences237–227 Mya — about 0.4 occurrences227–217 Mya — about 2 occurrences217–207 Mya — about 2 occurrences207–196 Mya — about 2 occurrences196–186 Mya — about 0.4 occurrences134–124 Mya — about 0.6 occurrences124–114 Mya — about 14 occurrences114–103 Mya — about 14 occurrences103–93 Mya — about 131 occurrences93–83 Mya — about 108 occurrences83–72 Mya — about 305 occurrences72–62 Mya — about 2113 occurrences62–52 Mya — about 7625 occurrences52–41 Mya — about 1053 occurrences41–31 Mya — about 58 occurrences31–21 Mya — about 38 occurrences21–10 Mya — about 169 occurrences10–0 Mya — about 357 occurrences298.9 Mya11.7 ka310 Mya0 Mya

12,000+ occurrences of Synapsida on record. The Paleobiology Database records this as a living group. 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

12,000 occurrences read

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. The read hit its cap, so every figure above is a floor and the shares are of the occurrences read. More on what this infers.

Found in

at least 173 formations

Willwood — 44.78°N, 108.97°WWillwood — 44.30°N, 109.00°WWillwood — 44.82°N, 109.05°WWillwood — 43.95°N, 107.57°WWillwood — 44.50°N, 108.00°WWillwood — 44.00°N, 108.00°WWillwood — 44.65°N, 108.54°WWillwood — 44.60°N, 108.32°WWillwood — 44.64°N, 108.43°WWillwood — 44.53°N, 108.39°WWillwood — 44.53°N, 108.32°WWillwood — 44.65°N, 109.93°WWillwood — 44.59°N, 108.86°WWillwood — 44.49°N, 108.54°WWillwood — 44.42°N, 108.69°WWillwood — 44.38°N, 108.80°WWillwood — 44.44°N, 108.63°WWillwood — 44.49°N, 108.81°WWillwood — 44.50°N, 108.67°WWillwood — 44.56°N, 108.70°WWillwood — 44.59°N, 108.62°WWillwood — 44.65°N, 108.76°WFort Union — 47.60°N, 107.00°WFort Union — 47.10°N, 104.80°WFort Union — 47.80°N, 106.10°WFort Union — 43.85°N, 108.35°WFort Union — 43.70°N, 108.70°WFort Union — 44.30°N, 109.00°WFort Union — 46.05°N, 104.48°WFort Union — 45.80°N, 104.40°WFort Union — 41.70°N, 109.00°WFort Union — 41.30°N, 107.74°WFort Union — 44.50°N, 108.00°WFort Union — 45.80°N, 109.80°WFort Union — 46.70°N, 101.80°WFort Union — 48.50°N, 101.90°WFort Union — 46.90°N, 101.50°WFort Union — 46.59°N, 101.74°WFort Union — 46.90°N, 103.90°WFort Union — 45.80°N, 110.50°WFort Union — 44.72°N, 108.38°WFort Union — 44.68°N, 108.32°WFort Union — 45.20°N, 109.00°WFort Union — 44.89°N, 108.93°WFort Union — 43.20°N, 107.10°WFort Union — 45.10°N, 106.90°WFort Union — 45.40°N, 105.60°WFort Union — 43.45°N, 109.16°WFort Union — 41.92°N, 108.56°WFort Union — 44.72°N, 108.62°WFort Union — 43.20°N, 108.20°WWasatch — 41.80°N, 110.70°WWasatch — 41.27°N, 110.33°WWasatch — 43.25°N, 110.42°WWasatch — 42.70°N, 110.10°WWasatch — 40.60°N, 108.10°WWasatch — 41.70°N, 109.00°WWasatch — 41.80°N, 107.00°WWasatch — 41.20°N, 110.50°WWasatch — 43.20°N, 108.20°WWasatch — 40.00°N, 107.90°WWasatch — 42.07°N, 109.10°WDeBeque — 40.00°N, 107.90°WDeBeque — 39.20°N, 108.20°WDeBeque — 39.27°N, 108.18°WDeBeque — 39.70°N, 107.60°WDeBeque — 38.70°N, 107.60°WWind River — 43.20°N, 107.10°WWind River — 44.00°N, 106.60°WWind River — 43.20°N, 108.20°WWind River — 41.60°N, 105.80°WWind River — 41.80°N, 107.00°WHell Creek — 47.63°N, 106.20°WHell Creek — 47.55°N, 107.12°WHell Creek — 47.62°N, 107.32°WHell Creek — 47.60°N, 107.00°WHell Creek — 47.80°N, 106.10°WHell Creek — 47.65°N, 106.65°WHell Creek — 47.52°N, 106.98°WHell Creek — 46.30°N, 104.50°WHell Creek — 47.57°N, 107.10°WHell Creek — 45.50°N, 103.10°WHell Creek — 47.52°N, 106.40°WHell Creek — 47.60°N, 106.38°WHell Creek — 47.58°N, 106.30°WHell Creek — 47.55°N, 107.25°WHell Creek — 47.87°N, 106.18°WHell Creek — 47.52°N, 107.18°WHell Creek — 47.53°N, 106.92°WHell Creek — 47.65°N, 106.20°WHell Creek — 47.07°N, 106.92°WHell Creek — 47.10°N, 104.80°WHell Creek — 47.70°N, 106.55°WHell Creek — 47.73°N, 106.50°WHell Creek — 45.40°N, 105.60°WHell Creek — 46.10°N, 103.30°WHell Creek — 47.60°N, 107.23°WHell Creek — 47.68°N, 106.43°WHell Creek — 46.90°N, 101.50°WHell Creek — 47.80°N, 106.21°WNacimiento — 36.30°N, 108.20°WNacimiento — 36.31°N, 108.00°WNacimiento — 35.70°N, 107.00°WNacimiento — 36.57°N, 107.97°WNacimiento — 36.18°N, 107.58°WNacimiento — 36.27°N, 107.76°WBridger — 42.70°N, 110.10°WBridger — 41.20°N, 110.50°WBridger — 41.50°N, 110.60°WBridger — 41.70°N, 109.00°WPaskapoo — 51.00°N, 114.10°WPaskapoo — 51.90°N, 113.30°WPaskapoo — 53.23°N, 114.70°WPaskapoo — 52.40°N, 113.80°WPaskapoo — 52.30°N, 113.80°WPaskapoo — 52.20°N, 113.70°WPaskapoo — 51.10°N, 114.50°WPaskapoo — 51.18°N, 114.43°WPaskapoo — 52.60°N, 114.10°WPaskapoo — 52.00°N, 114.30°WPaskapoo — 52.20°N, 113.60°WPaskapoo — 51.50°N, 112.30°WPaskapoo — 52.40°N, 116.10°WPaskapoo — 54.80°N, 115.46°WPaskapoo — 54.80°N, 115.80°WPaskapoo — 51.20°N, 112.50°WLance — 43.18°N, 104.53°WLance — 43.00°N, 104.50°WLance — 43.10°N, 104.60°WLance — 41.57°N, 108.67°WLance — 43.15°N, 104.57°WLance — 43.25°N, 104.65°WLance — 44.94°N, 108.85°WLance — 43.30°N, 104.37°WLance — 43.13°N, 104.49°WLance — 43.25°N, 104.52°WLance — 43.80°N, 104.62°WSan Jose — 36.50°N, 107.00°WSan Jose — 35.70°N, 107.00°W"Wasatch" — 44.50°N, 108.00°W"Wasatch" — 40.20°N, 109.90°W"Wasatch" — 44.00°N, 106.60°W"Wasatch" — 43.90°N, 105.70°WFerris — 41.94°N, 106.88°WFerris — 41.80°N, 107.00°WFerris — 41.96°N, 106.89°WFerris — 41.94°N, 106.85°WNorth Horn — 39.00°N, 111.00°WNorth Horn — 39.17°N, 111.27°WNorth Horn — 39.10°N, 111.80°WRavenscrag — 49.50°N, 109.20°WRavenscrag — 49.60°N, 108.70°WRavenscrag — 49.70°N, 110.10°WRavenscrag — 49.06°N, 102.75°WJudith River — 47.70°N, 110.70°WJudith River — 46.42°N, 109.27°WJudith River — 48.92°N, 110.58°WJudith River — 46.46°N, 109.41°WJudith River — 48.57°N, 109.68°WJudith River — 47.81°N, 109.59°WJudith River — 48.98°N, 110.52°WJudith River — 46.10°N, 109.10°WJudith River — 46.47°N, 109.30°WJudith River — 48.93°N, 110.65°WCedar Mountain — 39.00°N, 111.00°WCedar Mountain — 38.66°N, 111.24°WCedar Mountain — 38.94°N, 111.08°WBlack Peaks — 29.20°N, 103.20°WBlack Peaks — 29.28°N, 103.55°WBlack Peaks — 29.42°N, 103.10°WBlack Peaks — 29.46°N, 103.15°W"Fort Union" (= Lebo) — 46.20°N, 109.90°W"Fort Union" (= Lebo) — 45.80°N, 109.80°WLower Variegated Sequence — 43.90°N, 110.80°WLower Variegated Sequence — 43.20°N, 108.20°WHanna — 41.80°N, 107.00°WScollard — 52.33°N, 113.12°WScollard — 51.91°N, 112.97°WScollard — 51.80°N, 113.00°WNagri — 32.77°N, 72.50°EFrenchman — 49.50°N, 109.10°WFrenchman — 49.40°N, 107.40°WFrenchman — 49.30°N, 108.40°WFrenchman — 49.50°N, 109.20°WFrenchman — 49.20°N, 109.20°W

Loading coastlines…

The named rock units Synapsida has been recovered from, largest first. Drawn where the rock is now, not where it formed. The read hit its cap, so each count is a floor. 149 further formations hold fewer occurrences each and are not listed. 1,538 occurrences have no formation on record, which is common for older literature.

Found in the same rock

1,831 taxa

The Paleobiology Database records at least 462 sites for Synapsida, and this reads 240 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

at least 638 references

Each of the 12,000 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. That read hit its cap, so each count is a floor. 626 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 Synapsida

Credit
Nobu Tamura Max Bellomio Roman Uchytel Dmitry Bogdanov Fir0002 John and Karen, retouched by Zwoenitzer
Licence
Public Domain
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 itAmniota through timeThe world it lived on

Occurrence data from the Paleobiology Database, CC BY 4.0. (Osborn 1903)