Organism · Animals
Metaspriggina walcotti
Source time context (not species duration) · ≈ 539–487 Ma
Inferred life reconstruction
Metaspriggina walcotti
Overview
Metaspriggina walcotti is a Cambrian organism known for a small head, broad front body, and laterally flattened rear body. Its W-shaped muscle bands and internal pharyngeal bars have been studied. Several structures extending from the head into the trunk can be explored.[1]
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Key facts
An institutional account describes seven pairs of pharyngeal bars. These are internal structures. The outer outline and preserved internal supports provide different information.[1]
Time and place
An institutional account presents it as Middle Cambrian material from around 505 million years ago. The entire Cambrian spanned approximately 540–490 million years ago. Several internal structures have been used in research on early fishes.[2][4]
The time range describes source context, not the complete duration of this species.
Size, form and skeleton
A small head is followed by a broad front body and a laterally flattened rear body. W-shaped muscle bands are described along the trunk, with paired pharyngeal bars internally at the front. The eyes at the front and different trunk structures can be read separately.[1]
The museum photograph caption records specimen USNM198611 as 43 mm long.[2]
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Habitat and reproduction
How do internal bars and external muscle bands differ in what they reveal? Metaspriggina allows the supports of the pharynx to be compared with the arrangement of trunk muscles. Different tissues in a small body raise different questions.[1]
Fossil discovery
A museum account introducing a 2014 study explained the arrangement of the head, front and rear body, and W-shaped muscle bands. It also addressed seven pairs of pharyngeal bars. Several structures together contributed to understanding the body of an early fish.[1][3]
References
- Royal Ontario Museum — Introduction to the 2014 Metaspriggina study
- Metaspriggina walcotti
- Conway Morris·Caron (2014) — Early fishes from Cambrian North America
- International Commission on Stratigraphy (2024) — Geological time chart
- Li et al. 2020 — Vetulicola and small organisms living attached to its body
- Study — Morphology and relationships of vetulicolians
Research questions
Did the front and back of the body have the same form? Comparing the broad front body with the laterally flattened rear reveals different arrangements. Muscle bands and internal bars together help explain differences between regions.[1]
Observation
Move your gaze from the small head to the broad front body and flattened rear body. Considering the positions of W-shaped muscle bands and internal pharyngeal bars reveals several regions within this small body.[1]
Related organisms
Vetulicola cuneataAnimalsSource time context (not species duration) · ≈ 539–487 MaExploring front and rear bodies through Cambrian fossils
Explore the different records of bodies and time preserved by these two organisms. Metaspriggina walcotti is a Cambrian organism known for a small head, broad front body, and laterally flattened rear body. Its W-shaped muscle bands and internal pharyngeal bars have been studied. An institutional account presents it as Middle Cambrian material from around 505 million years ago. The entire Cambrian spanned approximately 540–490 million years ago. Vetulicola cuneata is a Cambrian organism whose front and rear regions differ markedly in shape. A body narrowing toward the front connects through a slender junction to a segmented posterior region. It is known through morphological and phylogenetic research on Cambrian vetulicolians. The Cambrian spanned approximately 540–490 million years ago.