Archotuba elongata (Luo & Hu in Luo et al., 1999)

By oilshale

• October 12, 2021

Taxonomy

Kingdom: Animalia
Phylum: incertae sedis
Class: incertae sedis
Order: incertae sedis
Family: incertae sedis
Genus: Archotuba
Species: Archotuba elongata
Author Citation (Luo & Hu in Luo et al., 1999)

Geological Time Scale

Eon: Phanerozoic
Era: Paleozoic
Period: Cambrian
Sub Period: None
Epoch: Series 2 Epoch
International Age: Stage 4

Stratigraphy

Wulongqing Formation

Provenance

Acquired by: Purchase/Trade

Dimensions

Length: 8 mm

Location

Gaoloufang (Village)
Chenggong (District)
Yunnan (Province)
China

• archotuba
• cambrian
• cnidaria
• gaoloufang
• priapulidae
• tff-oilshale-is2586
• yunnan

Comments

Synonym: †Archotuba conoidalis Hou et al., 1999,  †Cambrorhytium sp. Chen & Zhou, 1997

Quote from ‘The Cambrian Fossils of Chengjiang, China: The Flowering of Early Animal Life, Second Edition’: Hou Xian-Guang et al., p. 136: “This species is relatively common with hundreds of known specimens, which are essentially the remains of the tubes of the animal. All of the specimens are preserved as compressed fossils, in which a whitish color, sometimes with rusty patches. No proboscis or other soft parts of the animal have been discovered.

The tube is shaped like an elongated cone. Large individuals can reach 5cm in length and 6mm in diameter for the wide opening, with a sharply pointed posterior end. The surface of the tube is smooth and and lacks ornamentation, but a few specimens show sparsely distributed annulations. Parts of the intestine can be seen through the tube as a dark longitunal structure running down the midline of the fossil.

Archotuba is monospecific. A. elongata was originally reported as Selkirkia? elongata Luo & Hu, 1999. Chengjiang material recorded under the name Cambrorhytium sp. nov. of Chen & Zhou, 1997 and the species Archotuba conoidalis Hou et al., 1999 are considered to be the same species as A. elongata. A. elongata shows similarities to the other Cambrian tube-dwelling genera Selkirkia and Paraselkirkia and phylogenetic position of A. elongata remains problematic. It was originally assigned to Priapulida (Luo et al. 1999; Hou et al. 1999), but others have suggested that it might be related to cnidarians (Chen Jun-yuan & Zhou 1997; Chen Jun-yuan 2004; Huang 2005).”

This species is often found fixed to other creatures, and even clustered together with its own kind in similar orientations. A sessile lifestyle would suggest against an assignment to Priapulidae. However, if indeed they were sedentary like the cnidarians, no tentacles have been preserved to support such a conjecture.

References:

Luo Hui‐lin, Hu Shi‐xue, Chen Liang‐zhong, Zhang Shi‐shan & Tao Yong‐he (1999): Early Cambrian Chengjiang Fauna from Kunming Region, China. 129 pp, 32 pls. Yunnan Science and Technology Press, Kunming [in Chinese, with English summary].

The Cambrian Fossils of Chengjiang, China: The Flowering of Early Animal Life, Second Edition’: Hou Xian-Guang, David J. Siveter, Derek J. Siveter, Richard J. Aldridge, Cong Pei-Yun, Sarah E. Gabbott, Ma Xiao-Ma, Mark A. Purnell, Mark Williams (DOI:10.1002/9781118896372).

Luo Hui‐lin, Hu Shi‐xue, Chen Liang‐zhong, Zhang Shi‐shan & Tao Yong‐he (1999): Early Cambrian Chengjiang Fauna from Kunming Region, China. 129 pp, 32 pls. Yunnan Science and Technology Press, Kunming [in Chinese, with English summary]. 

Chen Jun‐yuan & Zhou Gui‐qing (1997): Biology of the Chengjiang fauna. Bulletin of the National Museum of Natural Science, 10, 11–106. 

Hou Xian‐guang, Bergström, J., Wang Hai‐feng, Feng Xiang‐ hong & Chen Ai‐lin (1999): The Chengjiang Fauna. Exceptionally Well‐Preserved Animals from 530 Million Years Ago. 170 pp. Yunnan Science and Technology Press, Kunming, Yunnan Province, China [in Chinese, with English summary]. 

Chen Jun‐yuan (2004): The Dawn of Animal World. 366pp.  Jiangsu Science and Technology Press, Nanjing, Jiangsu Province, China [in Chinese]. 

Chen Jun‐yuan & Zhou Gui‐qing (1997): Biology of the Chengjiang fauna. Bulletin of the National Museum of Natural Science, 10, 11–106. 

Huang Di‐ying (2005): Early Cambrian worms from SW China: morphology, systematics, lifestyles and evolutionary significance. PhD thesis, University Claude Bernard Lyon 1, France, 247 pp.