Cucumericrus
| Cucumericrus Temporal range:
| |
|---|---|
| File:20210207 Cucumericrus decoratus trunk appendage.png | |
| Trunk appengade of Cucumericrus decoratus | |
| Scientific classification Edit this classification | |
| Kingdom: | Animalia |
| Stem group: | Arthropoda |
| Genus: | †Cucumericrus Hou, Bergstrom & Ahlberg, 1995 |
| Type species | |
| Cucumericrus decoratus Hou, Bergstrom & Ahlberg, 1995
| |
Cucumericrus ("cucumber-leg") is an extinct genus of stem-arthropod. The type and only species is Cucumericrus decoratus, with fossils discovered from the Maotianshan Shales of Yunnan, China.[1]
Description
[edit | edit source]Cucumericrus is known from a few poorly preserved specimens.[1][2] Only fragments of trunk cuticle and corresponding appendages had been revealed, while features, such as head structures, which are important to determining its taxonomy, are unknown.[2][3] The trunk cuticle possess irregular wrinkles[1] and may had been soft in life.[4] Each of the trunk appendage compose of a dorsal flap-like element and a ventral stubby leg with unknown distal region,[1] structurally comparable to the trunk appendages of gilled lobopodians (dorsal flaps and ventral lobopods) and euarthropod biramous appendages (flap-like exopod and limb-like endopod).[3][5] Anterior margin of the flap lined with ray-like structures, similar to the body flaps of some radiodonts. The legs have been interpreted as somewhere between annulated lobopod legs and segmented arthropod legs.[4][5]
Taxonomic affinities
[edit | edit source]Cucumericrus was originally described as a radiodont alongside Parapeytoia, a genus with somewhat similar trunk appendages, but later revealed to be a megacheiran[6][7][8][9] being misinterpreted as a leg-bearing radiodont at that time.[1] The radiodont affinity of Cucumericrus remain questionable, since the presence of legs is unknown from any other radiodonts and no other radiodont key features (e.g. frontal appendages; oral cone; head sclerites) had been discovered. Only a few phylogenetic analysis including Cucumericrus, either resolving it in a polytomy between euarthropods and other radiodonts (alongside Caryosyntrips)[10][11] or closer to euarthropods (as a basal deuteropod) than radiodonts.[12]
See also
[edit | edit source]- Caryosyntrips, another stem-arthropod with similar uncertainties.
- Parapeytoia, a megacheiran once thought to be similarly leg-bearing radiodont.
- Erratus, a basal deuteropod with similar component of trunk appendages.
References
[edit | edit source]- ^ a b c d e Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ a b Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ a b Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ a b Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ a b Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
Lua error in Module:Taxonbar at line 165: attempt to index field 'wikibase' (a nil value).
