TSoSC #1: Lobster lunch of Luoping

Triassic Seas of South China #1: Lobster Lunch of Luoping

2013, acrylics on card/photography/2D digital

1st in a series for the following review paper =
Michael J. Benton, Qiyue Zhang, Shixue Hu, Zhong-Qiang Chen, Wen Wen, Jun Liu, Jinyuang Huang, Changyong Zhou, Tao Xie, Jinnan Tong & Brian Choo (accepted manuscript), Exceptional vertebrate biotas from the Triassic of China, and the expansion of marine ecosystems after the Permo-Triassic mass extinction, Earth Science Review. [link]

Recent discoveries of outstanding fossil biotas in Yunnan and Guizhou have provided an unparalleled glimpse of early Mesozoic marine life, from the shell-shocked aftermath of the Permian extinction to recovery and diversification in the Middle-Late Triassic.

ca. 245,000,000 bp, Middle Triassic (Anisian), Luoping County, Yunnan, China (Member II of the Guanling Formation)

A mere 8 million years after the worst mass extinction in Earth's history, life has well and truly recovered on a shallow muddy seafloor at the eastern edge of the Tethys Sea, off the west coast of the South China continent.

Just as tasty in the Triassic as they are today, an early rock lobster (Yunnanopalinura) attracts the unwanted attention of a coelacanth (Luopingcoelacanthus) and the armoured reptile Sinosaurosphargis, allowing a pair of horseshoe crabs to scuttle away unnoticed. Numerous other fish and marine reptiles swarm around in the warm sunlit waters.

DEPICTED TAXA
Invertebrates =
Yunnanopalinura schrami (9cm minus antennae). The world's oldest rock lobster (Palinuridae).
Yunnanolimulus luopingensis (4cm minus telson spike). Horseshoe crab.
Some generic ammonoids.

Fishes =
Luopingcoelacanthus eurylacrimalis (complete specimens at 20cm SL - isolated scales suggest individuals over thrice that length). Big blue coelacanth in the foreground.
Sangiorgioichthys sui (8cm SL) - numerous small fishes with black-tipped fins. The most common vertebrate in the assemblage.
Marcopoloichthys ani (3.5cm SL) - tiny fishes with red-spotted fins. Named after the famous explorer because fossils of this genus were almost simultaneously discovered in Italy and China.
Gymnoichthys inopinatus (13cm SL) - bright blue fish with yellow back.
Sinosaurichthys longimedialis (45cm SL) - needle-like fishes with flowing fins. Females are more robust and have shorter snouts. Sleek surface-to-midwater predators.
Kyphosichthys grandei (12cm SL) - pair of deep-bodied brown-yellow fishes at left.
Luoxiongichthys hyperdorsalis (15cm SL) - black & white banded deep-bodied fishes with high triangular dorsal crest.

Reptiles =
Sinosaurosphargis yunguiensis (60cm snout & carapace length, tail not preserved). The turtle-like thing in the foreground. Not a turtle, not a placodont but something else entirely. The saurosphargids were armoured aquatic diapsids of uncertain affinity. Thus we have three groups of Tethyan Triassic sauropsids that all independently acquired a turtle-like carapace (saurosphargids, placodonts and genuine turtles). Weird.

Dianopachysaurus dingi (25cm total length) small green reptile. A small pachypleurosauroid sauropterygian.

Mixosaurus cf.panxianensis (80cm total length) Small early ichthyosaurs (although the biggest animals in this scene). Based on a specimen erroneously described as the Swiss M.kuhnschnyderi, but closer to M. panxianensis from Yunnan. Although mixosaurs are often restored with dorsal fins, there is no firm evidence for this structure so early in the ichthyosaur lineage. Luoping and Panxian mixosaurs are often surrounded by a carbonaceous film that show no trace of a DF.