Teinolophos trusleri was a prehistoric species of monotreme, or egg-laying mammal. It is known from a lower jawbone found in Flat Rocks, Victoria, Australia. It lived during the Aptian age of the Lower Cretaceous. For other uses, see Scientific classification (disambiguation). ... For other uses, see Animal (disambiguation). ... Typical Classes See below Chordates (phylum Chordata) are a group of animals that includes the vertebrates, together with several closely related invertebrates. ... Subclasses & Infraclasses Subclass †Allotheria* Subclass Prototheria Subclass Theria Infraclass †Trituberculata Infraclass Metatheria Infraclass Eutheria Mammals (class Mammalia) are warm-blooded, vertebrate animals characterized by the production of milk in female mammary glands and by the presence of: hair, three middle ear bones used in hearing, and a neocortex region in... Families †Kollikodontidae Ornithorhynchidae Tachyglossidae †Steropodontidae Monotremes (monos, single + trema, hole; refers to the cloaca) are mammals that lay eggs instead of giving birth to live young like marsupials (Metatheria) and placental mammals (Eutheria). ... Binomial name Steropodon galmani Archer, Flannery, Ritchie, & Molnar, 1985 Steropodon galmani was a prehistoric monotreme, or egg-laying mammal species that lived during the middle Albian stage, in the Lower Cretaceous period. ... This article does not cite any references or sources. ... Prehistory (Greek words προ = before and ιστορία = history) is the period of human history prior to the advent of writing (which marks the beginning of recorded history). ... The hierarchy of scientific classification. ... Families †Kollikodontidae Ornithorhynchidae Tachyglossidae †Steropodontidae Monotremes (monos, single + trema, hole; refers to the cloaca) are mammals that lay eggs instead of giving birth to live young like marsupials (Metatheria) and placental mammals (Eutheria). ... Subclasses & Infraclasses Subclass †Allotheria* Subclass Prototheria Subclass Theria Infraclass †Trituberculata Infraclass Metatheria Infraclass Eutheria Mammals (class Mammalia) are warm-blooded, vertebrate animals characterized by the production of milk in female mammary glands and by the presence of: hair, three middle ear bones used in hearing, and a neocortex region in... “VIC” redirects here. ... In the geologic timescale, the Aptian is the age of the Lower Cretaceous epoch of the Cretaceous period of the Mesozoic era of the Phanerozoic eon that is comprehended between 125 and 112 million years ago, approximately. ... // The Cretaceous Period is one of the major divisions of the geologic timescale, reaching from the end of the Jurassic Period (i. ...

The species name honours the artist Peter Trusler. The genus name, Teinolophos, means 'extended ridge', a reference to its tooth structure. The hierarchy of scientific classification. ... Leptoceratops by Peter Trusler, 1999 Peter Trusler (fl. ... For other uses, see Genus (disambiguation). ...

Originally, Teinolophos was thought to be a eupanthothere. Further research revealed similarities to Steropodon, except in size: the animal was around 10 cm long. Binomial name Archer, Flannery, Ritchie, & Molnar, 1985 Steropodon galmani was a prehistoric species of monotreme, or egg-laying mammal, that lived during the middle Albian stage, in the Lower Cretaceous period. ...

The holotype is a partial left dentary known as NMV P208231. An age of approximately 123 million years makes this the earliest known monotreme. The lower molar is broadly similar in morphology to the m2 of Steropodon. The trigonid is compressed and the talonid has no basin. The dentary is about one sixth the size of Steropodon's, and wear facets indicate an "orthal" occlusion with the upper molars. A holotype is one of several possible types. ... The dentary is the tooth bearing bone of the lower jaw. ... The molar design that is considered one of the most important characteristics of mammals is a three-cusped shape called a tribosphenic molar. ... The molar design that is considered one of the most important characteristics of mammals is a three-cusped shape called a tribosphenic molar. ...

The construction of the lower jaw differs from existing monotremes. Among the contrasts are the condyle, which is well above the tooth row (instead of at about the same height); and the ascending ramus, which is also higher. Also different is that Teinolophos probably had a strong bite. A unique feature for known toothed monotremes is that the trigonid is tall, while the talonid is set much lower. This is more like the general mammalian arrangement. The molar is double-rooted, which is plesiomorphic when compared to ornithorhynchids, but is a shared characteristic with Steropodon and Kollikodon. Subsequent monotreme molars are multi-rooted. Categories: Move to Wiktionary | Anatomy stubs ... Ramus can refer to: Petrus Ramus A portion of a bone, as in the Ramus mandibulæ This is a disambiguation page: a list of articles associated with the same title. ... This cladogram shows the relationship among various insect groups. ... For other uses, see Platypus (disambiguation). ... Kollikodon is an extinct species of Monotreme. ...

The species has been placed in the Steropodontidae in some classifications. Binomial name Steropodon galmani Archer, Flannery, Ritchie, & Molnar, 1985 Steropodon galmani was a prehistoric monotreme, or egg-laying mammal species that lived during the middle Albian stage, in the Lower Cretaceous period. ...

See also

• Fossil Monotremes

Families †Kollikodontidae Ornithorhynchidae Tachyglossidae †Steropodontidae Monotremes (monos, single + trema, hole; refers to the cloaca) are mammals that lay eggs instead of giving birth to live young like marsupials (Metatheria) and placental mammals (Eutheria). ...

Links and References

• Rich et al. "Early Cretaceous Mammals from Flat Rocks, Victoria, Australia". Records of the Queen Victoria Museum, Launceston (1999).
• Rich, T. H., et al. "Monotreme nature of the Australian Early Cretaceous mammal Teinolophos". Acta Palaeontologica Polonica 46(1). 2001 Pages 113–118.
• Life in the Shadows, Non-reptilian life in Mesozoic Australia
• Mesozoic Mammals: Monotremata, an Internet directory
• "Prehistoric jawbone reveals evolution repeating itself" 10 February 2005