Sunday, May 17, 2015

[PaleoIchthyology • 2015] A Specimen of Paralycoptera Chang & Chou 1977 (Teleostei: Osteoglossoidei) from Hong Kong (China) with a potential Late Jurassic age that extends the Temporal and Geographical Range of the Genus


Paralycoptera sp. || Hong Kong’s first dinosaur-era fish - a specimen of the Chinese osteoglossoid osteoglossomorph fish 


Abstract

We describe a Mesozoic fish Paralycoptera sp. (Teleostei: Osteoglossoidei), on the basis of a postcranial skeleton collected from the volcaniclastic mudstones of the Lai Chi Chong Formation of Hong Kong, China. The new finding—representing the city’s first Mesozoic fish—extends the geographical distribution of Paralycoptera from eastern mainland China into Hong Kong, demonstrating a wider distribution than previously appreciated for this genus. A radiometric age for the Lai Chi Chong Formation of 146.6 ± 0.2 Ma implies a temporal range expansion for Paralycoptera of approximately 40 million years back from the Early Cretaceous (∼110 Ma). However, spores found in the Formation suggest an Early Cretaceous age that is consistent with the existing age assignment to Paralycoptera. We argue that the proposed temporal range extension is genuine because it is based on recent high precision radiometric age data, but given the discrepancies with the biostratigraphic ages further investigation is needed to confirm this. This study provides an important step towards revealing Hong Kong’s Mesozoic vertebrate fauna and understanding its relationship to well-studied mainland Chinese ones.


Figure 1: Hong Kong’s first dinosaur-era fish - a specimen of the Chinese osteoglossoid osteoglossomorph fish Paralycoptera sp. 
Image: IVPP

Figure 7: Skeletal reconstruction of Paralycoptera. Reconstructed skeleton of Paralycoptera
(Xu & Chang, 2009; used with the permission of the authors). 

Figure 4: Life reconstruction of Paralycoptera
Illustration: Wu Feixiang, IVPP

Systematic Palaeontology

SUBDIVISION TELEOSTEI Müller, 1846
SUPERORDER OSTEOGLOSSOMORPHA Greenwood et al., 1966

ORDER OSTEOGLOSSIFORMES Regan, 1909
SUBORDER OSTEOGLOSSOIDEI Regan, 1909

GENUS PARALYCOPTERA Chang & Chou, 1977

PARALYCOPTERA sp.


Lai Chi Chong’s rock strata
 photograph: Tse Tze-kei


Tze-Kei Tse, Michael Pittman​ and Mee-mann Chang. 2015. A Specimen of Paralycoptera Chang & Chou 1977 (Teleostei: Osteoglossoidei) from Hong Kong (China) with a potential Late Jurassic age that extends the Temporal and Geographical Range of the Genus. PeerJ. 3:e865. DOI: 10.7717/peerj.865

Hong Kong’s first identified dinosaur-era vertebrate 
HKU’s Department of Earth Sciences: the fish Paralycoptera lived in Lai Chi Chong more than 140 million years ago

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