| Basic info | Taxonomic history | Classification | Included Taxa |
| Morphology | Ecology and taphonomy | External Literature Search | Age range and collections |
Falloaster
Taxonomy
Falloaster was named by Blake et al. (2019).
It was assigned to Falloasteridae by Blake et al. (2019).
It was assigned to Falloasteridae by Blake et al. (2019).
Species
Synonymy list
| Year | Name and author |
|---|---|
| 2019 | Falloaster Blake et al. |
Is something missing? Join the Paleobiology Database and enter the data
|
|
If no rank is listed, the taxon is considered an unranked clade in modern classifications. Ranks may be repeated or presented in the wrong order because authors working on different parts of the classification may disagree about how to rank taxa.
Diagnosis
| Reference | Diagnosis | |
|---|---|---|
| D. B. Blake et al. 2019 | As for type species, by monotypy:
"Asterozoan with ambulacral dorsal surfaces traversed by two prominent lateral ridges separated by medial depressed area, together yielding bilateral ossicular shape. Lateral ridges together with upturned abradial and adradial margins of successive ambulacrals form elliptical surface leading to enlarged podial pore; pore not partially roofed by ledge. Ambulacral in ‘ventral’ aspect of ‘hourglass’ shape; pore where best-preserved edged by continuous circular rim. Figure 3. Semi-diagrammatic cross sections of arms of (1) generalized Ordovician early asteroid, order Euaxosida sensu Blake (2018) and (2) Falloaster anquiroisitus. Ambulacral of euaxosidan abuts adambulacral, which in turn abuts marginal, whereas ambulacral of F. anquiroisitus occupies full ventral and lateral arm margins. Podium outline of euaxosidan roofed by solid skeletal surface, a ‘podial basin,’ whereas large pores occur in F. anquiroisitus. Podial pore size in F. anquiroisitus might suggest presence of ampullae but awaits verification (see text on interpretation of water vascular tissues). Radial water vascular channel shown as small in euaxosidan, and although eroded, it might have been large in F. anquiroisitus, as in probable ancestral somasteroids. Abradial ambulacral margin sharply upturned to rim and support abactinal ossicles. No adambulacral or other virgal-series derivatives present. No ambital framework series, represented by marginal ossicles among asteroids, present. Dorsal arm surfaces on each side of arm midline formed by single series of enlarged, oblique rectangular, plate-like abactinals abutted at arm midline; configuration suggests carinal series absent. Skeleton of central portion of disk unknown. Remaining disk-edge ossicles consisting of two series, differing appearances suggesting possible partial exposure of both dorsal and ventral ossicles. Remaining arm-base ossicles similar to enlarged arm abactinals. Enlarged, semicircular madreporite(?) at disk edge." |
Measurements
No measurements are available
|
|
||||
|
|
||||
|
|||||
|
|||||
|
|
||||
|
|
||||
| Source: subp = subphylum, p = phylum | |||||
| References: Bambach et al. 2007, Aberhan 1992 | |||||
Age range: Blackhillsian or 475.30000 to 471.30000 Ma
Collections: one only
| Time interval | Ma | Country or state | Original ID and collection number |
|---|---|---|---|
| Blackhillsian | USA (Idaho) | F. anquiroisitus (206507) |