Early Devonian
E27677
The Early Devonian was the initial subdivision of the Devonian Period, marked by the diversification of early fishes and the spread of primitive vascular land plants across emerging terrestrial ecosystems.
Aliases (1)
Statements (49)
| Predicate | Object |
|---|---|
| instanceOf |
geologic time interval
→
subdivision of the Devonian Period → |
| associatedWith |
Rhynie Chert fossil locality
→
|
| boundaryDefinedBy |
Global Boundary Stratotype Section and Point at Klonk, Czech Republic
→
first appearance of the conodont Icriodus woschmidti → |
| characterizedBy |
brachiopod-rich marine faunas
→
development of early terrestrial ecosystems → diversification of early fishes → early ammonoid ancestors → evolution of early coral reefs → expansion of jawed fishes → expansion of terrestrial habitats along coastlines and floodplains → extensive shallow epicontinental seas → high sea levels → marine invertebrate diversification → presence of jawless agnathan fishes → spread of primitive vascular land plants → trilobite faunas in decline compared to earlier Paleozoic → warm global climate → |
| chronostratigraphicUnit |
Lower Devonian Series
→
|
| containsStage |
Emsian
→
Lochkovian → Pragian → |
| endTime |
approximately 393.3 million years ago
→
|
| fauna |
early acanthodian fishes
→
early placoderm fishes → jawless ostracoderms → lobe-finned sarcopterygian fishes → ray-finned actinopterygian fishes → rugose corals → stromatoporoid sponges → tabulate corals → |
| follows |
Pridoli Epoch
→
|
| geologicalSetting |
active orogeny in Caledonian mountain belts
→
assembly of Euramerica continent → |
| notableFossils |
Aglaophyton
→
Rhynia → early terrestrial arthropods in Rhynie Chert → |
| partOf |
Devonian Period
→
|
| plantFlora |
early lycophytes
→
primitive vascular plants → rhyniophytes → simple leafless stems with sporangia → zosterophylls → |
| precedes |
Middle Devonian
→
|
| startTime |
approximately 419.2 million years ago
→
|
| timeScale |
Paleozoic Era
→
Phanerozoic Eon → |
| usedIn |
International Commission on Stratigraphy timescale
→
|
Referenced by (3)
| Subject (surface form when different) | Predicate |
|---|---|
|
Early Devonian
("Lower Devonian Series")
→
|
chronostratigraphicUnit |
|
Old Red Sandstone
→
|
geologicPeriodStart |
|
Devonian Period
→
|
hasSubdivision |