Bajo de Véliz Formation
The Bajo de Véliz Formation is stratigraphic formation of the Paleozoic located in the Paganzo Basin, Argentina. This formation lies in the northwestern sector of San Luis, about 25 km west of Santa Rosa de Conlara. Containing a slice of the Carboniferous-Permian transition, it is one of the key upper Paleozoic successions characterizing that era in westernmost Gondwana, which South America was a part of in the Paleozoic. 

It consists of Cautana (Upper Carboniferous), Pallero (end-Pennsylvanian to Cisuralian), and Lomas (Permian) units. Based on the paleoflora found in the middle upper Pallero unit, it was suggested to be of earliest Cisuralian age of the early Permian, though there is still ambiguity as insects associated with that layer have been assigned to the late Pennsylvanian of the Carboniferous.

It is one of the key windows into the fossil life of the Gzhelian to Asselian, and is known as the formation where the thought-to-be-spider "Megarachne", actually a giant eurypterid, was discovered. 
Q134783
stratigraphic
Concept
Q75507
Paleozoic
LOC
None
Paganzo Basin
UNK
Q736917
formation
Concept
Q44818
San Luis
LOC
Q1018381
Santa Rosa de Conlara
LOC
Q133738
Carboniferous
LOC
Q76402
Permian
LOC
Q7632606
successions
Concept
Q80583
Gondwana
LOC
Q373772
Upper Carboniferous
TIME
Q373772
Pennsylvanian
TIME
Q642169
Cisuralian
Concept
Q192694
paleoflora
Concept
Q642169
Cisuralian
Concept
Q1030848
Gzhelian
TIME
Q740340
Asselian
TIME
Q141230
Megarachne
Concept
Q19436
eurypterid
Concept
Q25409085
Bajo de Véliz Formation
Concept
+25^^http://www.w3.org/2001/XMLSchema#decimal
25
NUMBER
instance of
follows
follows
follows
follows
parent taxon