Actinastrum sp.
Actinastrum is a genus of freshwater green algae. It was first described by Gustaf Lagerheim in 1882. Members of the genus are commonly found in eutrophic freshwater ponds and lakes, and have a cosmopolitan distribution.

Environmental Protection Agency · 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.
Time the record covers
At most 6.2 million years on record.
The one occurrence read is dated to somewhere between 72.2 Mya and 66 Mya, which is a dating window rather than a span.
1 occurrence of Actinastrum sp. on record, most of them in the Late 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
1 occurrences- Late Cretaceous100%
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.
Actinastrum sp. and its relatives
Late CretaceousWhere Actinastrum sp. and its relatives were recorded in the Late Cretaceous.
Found in the same rock
60 taxa- ? Colophidia indet.1 site
- Acrosphenodontia indet.1 site
- Aesculipollis sp.1 site
- Anguidae1 site
- Aniliidae1 site
- Anura1 site
- Apateodus striatus1 site
- Apogonidarum1 site
- Ariadnaesporites1 site
- Belonostomus1 site
- Charophyta1 site
- Cholophidia1 site
- Cingulatisporites1 site
- Clupeidarum1 site
- Crocodyliformes1 site
- Crybelosporites1 site
- Cyathidites australis1 site
- Dakshina jederi1 site
- Deccanolestes1 site
- Deccanolestes hislopi1 site
- Deccanolestes robustus1 site
- Discoglossidae1 site
- Echimonocolpites1 site
- Echistephanocolpites meghalayensis1 site
The Paleobiology Database records 1 site for Actinastrum sp., 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
1 referenceEach of the 1 occurrence 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. Each entry links to doi.org. Relayed as the Paleobiology Database holds them, not checked against what they resolve to.
Media and terms
Media content1
Picture of Actinastrum sp.
- Source
- Wikipedia/Commons
- Credit
- Environmental Protection Agency
- 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
- Source
- Wikipedia, “Actinastrum”
- 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 itFormations of the Late CretaceousThe world it lived on
Occurrence data from the Paleobiology Database, CC BY 4.0.