Kylinxia

Source: Wikipedia, the free encyclopedia.

Kylinxia
Temporal range:
Ma
↓
Artist's restoration, following three eye interpretation
Scientific classification
Kingdom:
Animalia
Phylum:
Arthropoda
Genus:
†Kylinxia
Species:
†K. zhangi
Binomial name
Kylinxia zhangi
Zeng et al., 2020

Kylinxia is a

Cambrian period.[2] Announcing the discovery on 4 November 2020 at a press conference, Zeng Han of the Nanjing Institute of Geology and Paleontology, said that the animal "bridges the evolutionary gap from Anomalocaris to true arthropods and forms a key ‘missing link’ in the origin of arthropods,"[3] which was "predicted by Darwin’s evolutionary theory."[4] The same day the formal description was published in Nature.[1]

Discovery

Kylinxia zhangi was discovered among the Maotianshan Shales from Yu'anshan Formation at Yunnan in southern China in 2019. Zeng Han, Zhao Fangchen, and Huang Diying of the Nanjing Institute of Geology and Palaeontology,

paratypes) are maintained at the Yingliang Stone Natural History Museum.[1]

Etymology

The genus name Kylinxia refers to a mixture of arthropod characters; kylin (qilin) is derived from the chimeric creature in Chinese mythology, while xia (蝦) is a Chinese word for shrimp-like arthropod. The species name zhang is after Yehui Zhang who contributed the additional specimens (paratypes).[1][2]

Description

Size chart
Frontalmost appendage of Kylinxia zhangi
Various interpretations of eye placement of Kylinxia.
A: 1 pair of large lateral eyes, 3 small median eyes after Zeng et al. (2020)[1]
B: 2 pairs of small lateral eyes, single large median eye after Moysiuk and Caron (2022)[5]
C: 1 pair of small lateral eyes, single large median eye, anterior sclerite present, after O’Flynn et al. (2023)[6]

Kylinxia is a tiny shrimp-like

radiodonts (frontalmost appendages) and megacheirans (trunk).[1]

The head of Kylinxia covered by a fused

great appendages of megacheirans, the head region of Kylinxia has a pair of unfused, 16-jointed frontalmost appendages each of which has terminal and paired, serrated inner spines (endites), similar to those seen in the radiodont[2] genera Anomalocaris (overall proportion) and Ramskoeldia (endites).[12][1] Unlike radiodonts, the frontalmost appendages face upward and lack outer spines, which is a feature shared by the great appendages of megacheirans.[8][1]

Similar to the multisegmented megacheirans, the trunk of Kylinxia covers most of the body length and is composed of up to 26

biramous) and all from head.[6] The remaining appendages are all biramous, with the leg-like inner branches (endopod) each composed of at least seven segments and the suboval outer branches (exopods) each possess marginal lamellae.[1] The triangular pygidium covers at least 5 pairs of appendages, terminated with a three-lobed tail fan consisting of a middle and a pair of lateral lobes as seen in several Cambrian arthropods such as hymenocarine and fuxianhuiids.[13]

Taxonomy

Kylinxia has generally been placed as one of the most basal members of Deuteropoda. A close relationship with the genus Fengzhengia has been proposed.[6]

See also

  • Erratus – Another taxon proposed to be transitional between radiodonts and euarthropods

References

  1. ^
    S2CID 226248177
    .
  2. ^ a b c Weisberger, Mindy (5 November 2020). "500 million-year-old creature with mashup of bizarre features could be arthropod 'missing link'". livescience.com. Retrieved 2023-12-17.
  3. ^ "Five-eyed fossil shrimp could be 'missing link' in arthropod evolution". The Japan Times. 2020-11-05. Archived from the original on November 4, 2020.
  4. ^ "Five eyes and quite a story to tell". Cosmos Magazine. 2020-11-04. Archived from the original on 2023-11-08.
  5. ISSN 0960-9822
    .
  6. ^
    ISSN 0960-9822
    .
  7. ^ de Lazaro, Enrico (6 November 2020). "Cambrian Shrimp-Like Arthropod Had Five Eyes". Sci-News.com. Archived from the original on 2023-11-08.
  8. ^
    doi:10.1080/00241160410004764
    .
  9. doi:10.1111/j.1502-3931.1986.tb00738.x
    .
  10. PMID 25750235
    .
  11. PMID 26678148
    .
  12. S2CID 90258934
    .
  13. doi:10.1111/let.12032
    .
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