Xujiachong Formation | |
---|---|
Stratigraphic range: Pragian | |
Type | Geological formation |
Underlies | Chuandong Formation |
Overlies | Guijiatun Formation |
Location | |
Region | Yunnan |
Country | China |
The Xujiachong Formation is an early Devonian formation from China. It preserves a wide range of plant and fish fossils, many being only known from this formation.
Color key
| Notes Uncertain or tentative taxa are in small text; |
Plants | |||||
---|---|---|---|---|---|
Genus | Species | Higher taxon | Notes | Images | |
Adoketophyton | A. subverticillatum | Lycophyta | Synonymous with “Zosterophyllum spathulatum” [1] | ![]() | |
Bracteophyton | B. variatum | Tracheophyta incertae sedis | Resembles lycophytes somewhat, but likely not one itself. [2] | ||
Drepanophycus | D. qujingensis | Drepanophycales | Formerly placed within D. spinaeformis [3] | ||
Guangnania | G. cuneata | Zosterophyllopsida | Unclear whether it truly is a zosterophyll, somewhat similar to Yunia [4] | ||
Hedeia | H. sinica | Progymnospermopsida | Resembles both seed plants and trimerophytes [4] | ||
Hsua | H. robusta, H. deflexa [5] | Rhyniophyta? [4] | |||
Huia | H. gracilis | Zosterophyllales? | More slender than the type species [6] | ||
Zosterophyllum | Z. yunnanicum, Z. australianum [7] | Zosterophyllales | Used to date the Xujiachong Formation [8] | ![]() |
Animals | |||||
---|---|---|---|---|---|
Genus | Species | Higher taxon | Notes | Images | |
Eugaleaspis | E. xujiachongensis [9] | Galeaspida | Formerly placed under “Galeaspis”, but this genus was preoccupied by the trilobite Galeaspis . | ||
Gantarostrataspis | G. gengi | Galeaspida | Mostly known from the Posongchong Formation [10] | ||
Mizia | M. longhuaensis, M. parvus | Yunnanolepididae | M. parvus formerly placed within Yunnanolepis [11] | ![]() | |
Neopetalichthys [12] | N. yenmenpaensis | Petalichthyida | Relatively basal member of the clade [13] | ![]() | |
Pampetalichthys | P. longhuaensis | Petalichthyida | Formerly classed as “Holopetalichthys” [14] [15] | ||
Pterogonaspis | P. yuhaii | Galeaspida | Similar to Tridenaspis [16] | ||
Qushiaspis | Q. elaia | Galeaspida | Most basal member of Gantarostrataspididae. [17] | ||
Sanqiaspis | S. rostrata | Galeaspida | Another species known from Vietnam [18] | ||
Sanchaspis | S. magalarostrata | Galeaspida | Bears an unusual mushroom-shaped rostrum [19] | ||
Szelepis | S. yunnanensis | Actinolepididae | Redescribed in 2017 [20] | ||
Xichonolepis | X. qujingensis [21] | Sinolepidae (Antiarchi) | |||
Youngolepis | Y. praecursor | Dipnoi | Known from various other formations in early Devonian China [22] | ![]() |