| Cambropodus Temporal range: Wuliuan, | |
|---|---|
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Class: | incertae sedis |
| Genus: | † Cambropodus Robison, 1990 |
| Species: | †C. gracilis |
| Binomial name | |
| †Cambropodus gracilis Robison, 1990 | |
Cambropodus is a genus of Cambrian arthropod from the Wheeler Shale of Utah. It contains one species, Cambropodus gracilis. [1]
Cambropodus is only known from a partial specimen preserving what seems to be the front end of the body. It preserves nine pairs of appendages, all uniramous and likely used for walking, which bear some similarity to the legs of Scutigeromorpha. Due to their flexibility, they likely had between four and six podomeres, although the exact amount is unclear. The head also preserves two long antenniform structures. However, unlike myriapods, Cambropodus has no specialised head limbs, and instead the first two limb pairs are very similar to the rest. On the head, the limbs are more laterally attached, however they become more ventrally attached on the body. The complete animal is estimated to be roughly 2 cm long, with at least 15 pairs of appendages. The gut is preserved as a light stripe down the middle of the fossil, with no apparent gut diverticula and a likely very long midgut. No respiratory organs are preserved, therefore it likely respired through its thin exoskeleton. Cambropodus shares many similarities to the enigmatic fossil Portalia especially in the limbs, however it may be more derived and closer to Arthropoda due to the antenniform structures and apparently jointed legs. In this it resembles the myriapods more, however it is over 75 million years older than the oldest definitive myriapod, Kampecaris . [1] Cambropodus was likely cursorial and epibenthic, as evidenced by the structure of its legs closely matching other fast arthropods. The placement of this genus within Arthropoda is uncertain, as only the front portion is preserved, alongside no clear specialisation in head limbs that would place it within Mandibulata alongside the other myriapods.
Cambropodus is an arbitrary combination of letters which derives from the age of the fossil and the arthropodan affinity of the animal. The species name gracilis comes from the Latin word for "slender", referring to the legs of the animal. [1]
Uniramia is a group within the arthropods. In the past this group included the Onychophora, which are now considered a separate category. The group is currently used in a narrower sense.
Opabinia regalis is an extinct, stem group arthropod found in the Middle Cambrian Burgess Shale Lagerstätte of British Columbia. Opabinia was a soft-bodied animal, measuring up to 7 cm in body length, and its segmented trunk had flaps along the sides and a fan-shaped tail. The head shows unusual features: five eyes, a mouth under the head and facing backwards, and a clawed proboscis that probably passed food to the mouth. Opabinia probably lived on the seafloor, using the proboscis to seek out small, soft food. Fewer than twenty good specimens have been described; 3 specimens of Opabinia are known from the Greater Phyllopod bed, where they constitute less than 0.1% of the community.
Myriapods are the members of subphylum Myriapoda, containing arthropods such as millipedes and centipedes. The group contains about 13,000 species, all of them terrestrial.
Eurypterids, often informally called sea scorpions, are a group of extinct arthropods that form the order Eurypterida. The earliest known eurypterids date to the Darriwilian stage of the Ordovician period 467.3 million years ago. The group is likely to have appeared first either during the Early Ordovician or Late Cambrian period. With approximately 250 species, the Eurypterida is the most diverse Paleozoic chelicerate order. Following their appearance during the Ordovician, eurypterids became major components of marine faunas during the Silurian, from which the majority of eurypterid species have been described. The Silurian genus Eurypterus accounts for more than 90% of all known eurypterid specimens. Though the group continued to diversify during the subsequent Devonian period, the eurypterids were heavily affected by the Late Devonian extinction event. They declined in numbers and diversity until becoming extinct during the Permian–Triassic extinction event 251.9 million years ago.
Arthropleura is a genus of massive myriapod that lived in what is now Europe and North America around 345 to 290 million years ago, from the Viséan stage of the lower Carboniferous Period to the Sakmarian stage of the lower Permian Period. It is related to millipedes, and was capable of reaching at least 2 metres in length, possibly up to over 2.5 metres, making it the largest known land arthropod of all time. Arthropleura is known from body fossils as well as trace fossils, particularly giant trackways up to 50 centimetres (20 in) wide, and potentially also large burrows. It lived in open, sparsely wooded environments near water, and was possibly amphibious.
The arthropod leg is a form of jointed appendage of arthropods, usually used for walking. Many of the terms used for arthropod leg segments are of Latin origin, and may be confused with terms for bones: coxa, trochanter, femur, tibia, tarsus, ischium, metatarsus, carpus, dactylus, patella.
Waptia is an extinct genus of arthropod from the Middle Cambrian of North America. It grew to a length of 6.65 cm (3 in), and had a large bivalved carapace and a segmented body terminating into a pair of tail flaps. It was an active swimmer and likely a predator of soft-bodied prey. It is also one of the oldest animals with direct evidence of brood care. Waptia fieldensis is the only species classified under the genus Waptia, and is known from the Burgess Shale Lagerstätte of British Columbia, Canada. Specimens of Waptia are also known from the Spence Shale of Utah, United States.
The (pan)arthropod head problem is a long-standing zoological dispute concerning the segmental composition of the heads of the various arthropod groups, and how they are evolutionarily related to each other. While the dispute has historically centered on the exact make-up of the insect head, it has been widened to include other living arthropods, such as chelicerates, myriapods, and crustaceans, as well as fossil forms, such as the many arthropods known from exceptionally preserved Cambrian faunas. While the topic has classically been based on insect embryology, in recent years a great deal of developmental molecular data has become available. Dozens of more or less distinct solutions to the problem, dating back to at least 1897, have been published, including several in the 2000s.
Mixopterus is a genus of eurypterid, an extinct group of aquatic arthropods. Fossils of Mixopterus have been discovered in deposits from Late Silurian age, and have been referred to several different species. Fossils have been recovered from two continents; Europe and North America.
Onychopterella is a genus of predatory eurypterid, an extinct group of aquatic arthropods. Fossils of Onychopterella have been discovered in deposits from the Late Ordovician to the Late Silurian. The genus contains three species: O. kokomoensis, the type species, from the Early Pridoli epoch of Indiana; O. pumilus, from the Early Llandovery epoch of Illinois, both from the United States; and O. augusti, from the Late Hirnantian to Early Rhuddanian stages of South Africa.
Arthropods are invertebrates in the phylum Arthropoda. They possess an exoskeleton with a cuticle made of chitin, often mineralised with calcium carbonate, a body with differentiated (metameric) segments, and paired jointed appendages. In order to keep growing, they must go through stages of moulting, a process by which they shed their exoskeleton to reveal a new one. They form an extremely diverse group of up to ten million species.
Bradoriida, also called bradoriids, are an extinct order of small marine arthropods with a bivalved carapace, which globally distributed, forming a significant portion of the Cambrian and Early Ordovician soft-bodied communities.
Hibbertopteridae is a family of eurypterids, an extinct group of aquatic arthropods. They were members of the superfamily Mycteropoidea. Hibbertopterids were large, broad and heavy animals unlike virtually every other group of eurypterids, which are commonly streamlined and lightweight. Their bizarre morphology is so unusual that they in the past have been thought to represent an entirely distinct order of chelicerates. Fossils of the family first appear in deposits of Middle Devonian age and the last known fossils representing hibbertopterids are known from deposits of Late Permian age. The hibbertopterids represent the last known living eurypterids, going extinct during the Permian–Triassic extinction event or shortly before.
Slimonidae is a family of eurypterids, an extinct group of aquatic arthropods. Slimonids were members of the superfamily Pterygotioidea and the family most closely related to the derived pterygotid eurypterids, which are famous for their cheliceral claws and great size. Many characteristics of the Slimonidae, such as their flattened and expanded telsons, support a close relationship between the two groups.
Necrogammarus salweyi is the binomial name applied to an arthropod fossil discovered in Herefordshire, England. The fossil represents a fragmentary section of the underside and an appendage of a pterygotid eurypterid, a group of large and predatory aquatic arthropods that lived from the late Silurian to the late Devonian. The Necrogammarus fossil is Late Silurian in age and its generic name means "dead lobster", deriving from Ancient Greek νεκρός and Latin gammarus ("lobster").
Borchgrevinkium is an extinct genus of chelicerate arthropod. A fossil of the single and type species, B. taimyrensis, has been discovered in deposits of the Early Devonian period in the Krasnoyarsk Krai, Siberia, Russia. The name of the genus honors Carsten Borchgrevink, an Anglo-Norwegian explorer who participated in many expeditions to Antarctica. Borchgrevinkium represents a poorly known genus whose affinities are uncertain.
Retifacies abnormalis is an extinct arthropod that lived in the lower Cambrian. Its fossil remains have been found in the Maotianshan Shales of Yunnan, China. It is a member of the Artiopoda, and closely related to Pygmaclypeatus.
Terropterus is a genus of eurypterid, an extinct group of aquatic arthropods. The type and only species of Terropterus, T. xiushanensis, is known from deposits of Early Silurian age in China.
Balhuticaris is a genus of extinct bivalved hymenocarine arthropod that lived in the Cambrian aged Burgess Shale in what is now British Columbia around 506 million years ago. This extremely multisegmented arthropod is the largest member of the group, and it was even one of the largest animals of the Cambrian, with individuals reaching lengths of 245 mm (9 in). Fossils of this animal suggests that gigantism occurred in more groups of Arthropoda than had been previously thought. It also presents the possibility that bivalved arthropods were very diverse, and filled in a lot of ecological niches.
Apankura is an extinct genus of Cambrian euthycarcinoids from the Santa Rosita Formation of Argentina. The genus contains a single species, Apankura machu. It was at one point the only Cambrian euthycarcinoid. However, Mosineia and Mictomerus are likely older.