Semiacontiodus

Viira, Viive · CC BY-NC 4.0 · via GBIF. 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
- OneotodontidaePBDB
- Diet
- carnivorePBDB, for Conodonta
- Life habit
- nektonicPBDB, for Conodonta
- Motility
- actively mobilePBDB, for Conodonta
- Vision
- well-developedPBDB, for Conodonta
Time the record covers
At least 30 million years on record.
The record covers at least 486.85 Mya to 456.8 Mya. No occurrence read is dated outside 538.8 Mya to 443.1 Mya.
118 occurrences of Semiacontiodus on record, most of them in the Ordovician. 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
118 occurrences- Cambrian20%
- Ordovician80%
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
40 formations
- Öland C Formation14
- San Juan Formation11
- Toila Formation10
- Tribes Hill Formation · Beekmantown Group7
- Survey Peak Formation · McKay Group6
- Adze Formation5
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The named rock units Semiacontiodus has been recovered from, largest first. Drawn where the rock is now, not where it formed. 16 further formations hold fewer occurrences each and are not listed. 6 occurrences have no formation on record, which is common for older literature.
Semiacontiodus and its relatives
OrdovicianWhere Semiacontiodus and its relatives were recorded in the Ordovician.
Found in the same rock
425 taxa- Drepanoistodus basiovalis35 sites
- Acodus similaris32 sites
- Cornuodus longibasis28 sites
- Baltoniodus27 sites
- Teridontus nakamurai24 sites
- Paroistodus originalis22 sites
- Protopanderodus rectus21 sites
- Cordylodus proavus20 sites
- Decoriconus20 sites
- Protopanderodus20 sites
- Microzarkodina19 sites
- Ansella jemtlandica17 sites
- Parapaltodus17 sites
- Scolopodus striatus17 sites
- Scalpellodus16 sites
- Cordylodus intermedius15 sites
- Fahraeusodus15 sites
- Baltoniodus medius14 sites
- Cordylodus14 sites
- Periodon macrodentatus14 sites
- Drepanoistodus forceps13 sites
- Eoconodontus notchpeakensis13 sites
- Erraticodon13 sites
- Lenodus variabilis13 sites
The Paleobiology Database records 102 sites for Semiacontiodus, 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
33 references- Conodont biostratigraphy and global correlation of the middle Darriwilian-lower Sandbian (Ordovician) Las Aguaditas Formation, Precordillera of San Juan, Argentina15
- The conodont fauna in the Middle Ordovician Eoplacognathus pseudoplanus Zone of Baltoscandia14
- An Early to Middle Ordovician succession of conodont faunas at Mäekalda, northern Estonia14
- Legend of the Central European series of sheets of the State Geological Map of the Russian Federation, scale 1:1,000,000 (third generation)7
- Uppermost Cambrian and Lower Ordovician conodont biostratigraphy of the Survey Peak Formation (Ibexian/Tremadoc), Wilcox Pass, Alberta, Canada6
- Integrated Upper Ordovician - lower Silurian biostratigraphy of the Grötlingbo-1 core section, Sweden5
- Conodonts, Stratigraphy, and Relative Sea-Level Changes of the Tribes Hill Formation (Lower Ordovician, East-Central New York)5
- The recommended Cambrian - Ordovician global Boundry stratotype of the Xiaoyangqiao section (Dayangcha, Jilin Province), China5
- Late Cambrian and Early Ordovician Conodonts from the Franklinian Miogeosyncline, Canadian Arctic Islands4
- Ordovician Sedimentary Basin and Paleobiotas of the Gorny Altai3
- Conodonts from the Hwajeol Formation (Upper Cambrian) in the Seokgaejae area, southeast margin of the Taebaeksan Basin3
- An integrated biostratigraphical analysis of the Volkhov–Kunda (Lower Ordovician) succession at Fågelsång, Scania, Sweden3
Each of the 118 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. 21 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 Semiacontiodus
- Source
- GBIF
- Credit
- Viira, Viive
- Licence
- CC BY-NC 4.0
- Commercial use
- the licence does not allow it
No 3D scan of Semiacontiodus 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.
This is what the site found, which is not the same as what exists.
Keep going
What may have been alongside itOneotodontidae through timeFormations of the OrdovicianThe world it lived on
Occurrence data from the Paleobiology Database, CC BY 4.0.