![]() | This article includes a list of general
references, but it lacks sufficient corresponding
inline citations. (January 2013) |
Xenusion auerswaldae Temporal range:
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Fossil specimen | |
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Life restoration | |
Scientific classification
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Domain: | Eukaryota |
Kingdom: | Animalia |
(unranked): | Panarthropoda |
Phylum: | † "Lobopodia" |
Class: | † Xenusia |
Order: | † Protonychophora |
Family: | † Xenusiidae |
Genus: | †
Xenusion Pompeckj, 1927 |
Species: | †X. auerswaldae
|
Binomial name | |
†Xenusion auerswaldae Pompeckj, 1927
|
Xenusion auerswaldae is an early lobopodian known from two specimens found in glacial erratics on the Baltic coast of Germany. [1] They probably originated in the Kalmarsund Sandstone of Southern Sweden, [2] which was deposited in the Lower Cambrian (Upper Tommotian–Lower Atdabanian; Stages 2→3). [3] It is the oldest currently known lobopodian with soft body fossils. [4]
The specimens are not especially well preserved. The older specimen is 10 cm or so in length with a narrow, weakly segmented body. Assuming it was the posterior section, the specimen was estimated to be part of an animal about 20 cm in length. [1] A depression runs up the bottom on all but the rearmost segments. There is a slightly bulbous termination, and each segment before that seems to have a single pair of tapering annulated legs similar to the modern onychophoran, but without specialized feet and claws. More than 10 body segments were present. [5] There is presumably a spine on each body bump and faint transverse parallel striations on the annulations on the legs. [1] [5] The legs of what is possibly the foremost segments are either absent or not preserved. The head is believed to be missing or poorly preserved. Based on a new specimen that shows the anterior section, it possibly had a long narrow proboscis, [1] but this also suggested to be a preservational artefact. [6]
Xenusion has been reinterpreted as an Ediacaran frond animal by Tarlo, and a drawing of that interpretation has been presented by McMenamin. [7] In a photograph presented in The Treatise on Invertebrate Paleontology Volume O, the organism's appearance seems to support the original interpretation more. Further studies of Xenusiid close the possibility of a Rangeomorphy affinity. [1] [5]
![]() | This article includes a list of general
references, but it lacks sufficient corresponding
inline citations. (January 2013) |
Xenusion auerswaldae Temporal range:
| |
---|---|
![]() | |
Fossil specimen | |
![]() | |
Life restoration | |
Scientific classification
![]() | |
Domain: | Eukaryota |
Kingdom: | Animalia |
(unranked): | Panarthropoda |
Phylum: | † "Lobopodia" |
Class: | † Xenusia |
Order: | † Protonychophora |
Family: | † Xenusiidae |
Genus: | †
Xenusion Pompeckj, 1927 |
Species: | †X. auerswaldae
|
Binomial name | |
†Xenusion auerswaldae Pompeckj, 1927
|
Xenusion auerswaldae is an early lobopodian known from two specimens found in glacial erratics on the Baltic coast of Germany. [1] They probably originated in the Kalmarsund Sandstone of Southern Sweden, [2] which was deposited in the Lower Cambrian (Upper Tommotian–Lower Atdabanian; Stages 2→3). [3] It is the oldest currently known lobopodian with soft body fossils. [4]
The specimens are not especially well preserved. The older specimen is 10 cm or so in length with a narrow, weakly segmented body. Assuming it was the posterior section, the specimen was estimated to be part of an animal about 20 cm in length. [1] A depression runs up the bottom on all but the rearmost segments. There is a slightly bulbous termination, and each segment before that seems to have a single pair of tapering annulated legs similar to the modern onychophoran, but without specialized feet and claws. More than 10 body segments were present. [5] There is presumably a spine on each body bump and faint transverse parallel striations on the annulations on the legs. [1] [5] The legs of what is possibly the foremost segments are either absent or not preserved. The head is believed to be missing or poorly preserved. Based on a new specimen that shows the anterior section, it possibly had a long narrow proboscis, [1] but this also suggested to be a preservational artefact. [6]
Xenusion has been reinterpreted as an Ediacaran frond animal by Tarlo, and a drawing of that interpretation has been presented by McMenamin. [7] In a photograph presented in The Treatise on Invertebrate Paleontology Volume O, the organism's appearance seems to support the original interpretation more. Further studies of Xenusiid close the possibility of a Rangeomorphy affinity. [1] [5]