Lashanichthys sui (López-Arbarello et al. 2011)

By oilshale

• September 11, 2021

Taxonomy

Kingdom: Animalia
Phylum: Chordata Haeckel 1874
Class: Actinopteri Cope 1871
Order: Kyphosichthyiformes Sun and Ni 2017
Family: Lashanichthyidae Xu et al. 2019
Genus: Lashanichthys
Species: Lashanichthys sui
Author Citation (López-Arbarello et al. 2011)

Geological Time Scale

Eon: Phanerozoic
Era: Mesozoic
Period: Triassic
Sub Period: None
Epoch: Middle
International Age: Anisian (Pelsonian)

Stratigraphy

Guanling Formation
Vertebrate Level

Provenance

Acquired by: Purchase/Trade

Dimensions

Length: 5 cm

Location

Dawazi Town
Luoping County
Yunnan Province
China

• anisian
• dawazi
• guanling formation
• luoping
• sangiorgioichthys
• tff-oilshale-ch2576
• triassic
• †lashanichthys

Comments

The fish was described in 2011 by López-Arbarello et al. under the name Sangiorgioichthys sui and transferred by Xu et al. in 2019 to the newly erected genus Lanshanichthys.

Alternative combination: †Sangiorgioichthys sui López-Arbarello et al. 2011.

Taxonomy according to Fossilworks.org.

Diagnosis for the genus Lanshanichthys from Xu et al 2019, p. 185: “Nasal narrow and curved; frontal 1.8 times as long as parietal; presence of two to four supraorbitals; seven or eight infraorbitals, including two or three between lacrimal and posteroventral infraorbital; three or four suborbitals, separated by posteroventral infraorbital into two or three dorsal ones and single ventral one; presence of preopercle/ dermopterotic contact; supramaxilla nearly half of length of maxilla (excluding anteromedial process); opercle 2.2–3.0 times as deep as subopercle (excluding anterodorsal process); median gular nearly circular, 0.4 times as long as lower jaw; 19–21 principal caudal rays.”

Diagnosis of the species Sangiorgioichthys sui according to López-Arbarello et al. 2011, p. 27: “Species of Sangiorgioichthys Tintori and Lombardo, 2007, distinguished by the following combination of features: two pairs of extrascapular bones, the medial paired usually fused to the parietals; maxilla with a complete row of small conical teeth; supramaxilla long, more than half of the length of the maxilla; only two large suborbital bones posterior to the orbit, a dorsal smaller and a ventral much larger elements; flank scales with finely serrated posterior borders.

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Description of the species Sangiorgioichthys sui according to López-Arbarello et al. 2011, p. 28: “Resembling the other species of this genus, Sangiorgioichthys sui n. sp. is a rather small and fusiform fish (Fig. 2). The standard length (SL) of the holotype is 81 mm, the total length being >105 mm and the maximum body-depth 30 mm: the ratio of body-length vs. body-depth is 3.5. The orbit is about 9 mm, 32% of the head length. The studied specimens vary between 42 mm and 124 mm SL. The length of the head ranges between 29–43 % of the SL, showing a nice negative correlation with the size of the specimens, i.e. the smaller individuals have larger heads and vice versa (Fig. 3: HL/SL). The opposite trend is observed in the depth of the body, which ranges between 34–49% of the SL from smaller to larger individuals (Fig. 3:BD/SL).”

Reconstruction according to López-Arbarello et al. 2011, p. 28:

Identified by oilshale using López-Arbarello et al. 2011.

References:

López-Arbarello, A., Sun, Z. Y., Sferco, E., Tintori, A., Xu, G. H., Sun, Y, L., Wu F. X., and Jiang, D. Y. (2011): New species of Sangiogioichthys Tintori and Lombardo, 2007 (Neopterygii, Semionotiformes) from the Anisian of Luoping (Yunnan Province, South China). Zootaxa 2749:25-39. DOI: 10.11646/zootaxa.2749.1.2 

Sun Z. Y., Ni P. G., (2018): Revision of Kyphosichthys grandei Xu & Wu, 2012 from the Middle Triassic of Yunnan Province, South China: implications for phylogenetic interrelationships of ginglymodian fishes. J. Syst Palaeont, 16: 67– 85. DOI: 10.1080/14772019.2016.1269049

Xu G. H., Ma, X. Y., Wu, F. X., and Y. Ren, Y. (2019): A Middle Triassic kyphosichthyiform from Yunnan, China, and phylogenetic reassessment of early ginglymodians. Vertebrata PalAsiatica 57:181-204.  DOI: 10.19615/j.cnki.1000-3118.190319