Mammalia

From Palaeos.org

Contents 1 Introduction 2 Descriptions 3 Phylogeny 4 References

Introduction

This section covers mainly the Mesozoic mammals, together with the monotremes. One of the major problems in this area is Dr. Thomas Rich. That is, everyone else seems fairly happy with the current arrangement, save that Dr. Rich keeps finding jaw bones that look for all the world like placental mammal (eutherian) bones, but are (a) older than any placental mammal ought to be and (b) located in Australia -- a placenta-free zone. Rich et al. (2001). The (now) conventional wisdom is that the characterstic "tribosphenic" molars of mammals evolved twice and that Dr. Rich's specimens are the results of convergent evolution in some monotreme ancestors, Australosphenida, and not placentals misplaced in time and space, Ausktribosphenidae. Luo et al. (2001a); Luo et al. (2002). With the unyeilding commitment to principled choice which characterizes our commentary, we have used both terms. This reflects the fact that, while we officially think Dr. Rich is wrong, we also have a sneaking suspiscion that he may be right. In either event, we are now completely prepared to claim that we supported the winner all along, no matter who may prevail.

The following is a condensed reminder of some of the many changes from basal synapsids to basal mammals. Beyond this level, there appears to be an unreasonable amount of disagreement on the phylogenetic branching order. I have recently seen two completely different published phylogenies of basal mammals, both in standard texts, and both of which purported to rely on exactly the same reference!

1. Metabolic rate: transition to more or less full homeothermy inferred from geographic range, nocturnal habit, etc.

2. Temporal fossa: increase in size; confluence with orbit.

3. Zygomatic Arch: development; replacement of jaw adductor by masseter as principal jaw muscle; greatly increased capacity for oral processing of food.

4. Lower jaw: dentary becomes only significant element of mandible; development of coronoid process; reduction of post-dentary elements; reflected lamina of angular; dentary-squamosal jaw articulation. See infra, ear.

5. Dentition: development of heterodont dentition with incisors, canines, premolars and molars; "permanent" (diphyodont) teeth with prismatic enamel; increasingly fixed pattern of occlusion; definite dental formula.

6. Palate: full secondary palate.

7. Ear: reflected lamina of the angular (tympanic); retroarticular process of articular; conversion of post-dentary bones to sensory use in middle ear. Reflected lamina may have been resonating chamber, followed by development of tympanic membrane framed by increasingly small and gracile reflected lamina and/or retroarticular process.

8. Pineal foramen: pineal foramen initially becomes more conspicuous, then recedes and is lost.

9. Skull table: development of parietal crest with muscular attachment on outside of dermal bones.

10. Braincase: parietal and squamosal spread downward to cover braincase, gradually replacing (in advanced mammals) neurocranium while providing muscle attachment on lateral (formerly dorsal) surface; epipterygoid changes from pillar supporting parietal and braincase to alisphenoid element of skull, continuous with parietal, squamosal and petrosal (fused otic capsule). Brain size does not increase relative to diapsids.

11. Skull fusions: fusion of parietals and frontals, otic capsule, occipitals, numerous other elements in therians; loss of dermal bones, e.g. post-orbitals.

12. Skull attachment: double occipital condyle, condyles move ventrally, development of mammalian circular form.

13. Spine: loss of lumbar ribs (reversed in advanced cynodonts & lost again in Mammalia); increase in number of sacral vertebrae (??); reduction of tail; vertebral articulations changed to accommodate dorsoventral undulation; vertebrae amphiplatyan (flat on both ends), implying loss of notochord remnants (?).

14. Limb girdles: reduction (e.g. pubes, coracoids) or loss of ventral elements; more vertical orientation of limbs.

15. Limbs: more vertical orientation; elongation of humerus & femur; digits shorter; calcaneal heel.

16. Integument: fur?; mammalian muzzle

17. Habit: primitively large carnivores; great reduction in size; development of omnivorous and herbivorous adaptations.

Descriptions

Mammalia: Crown group mammals, i.e. Knuckles the Echidna + Suleiman the Magnificent.

Range: from the Middle Jurassic.

Phylogeny: Symmetrodonta : Kuehneotheriidae + * : Australosphenida + (Triconodonta + (Spalacotheroidea + Cladotheria)).

Characters: $? dentary condyle above the postcanine alveolar level [L+01]; $? masseteric fossa ventral ridge present [L+01]; $ overhanging medial ridge above the post dentary trough absent [L+01]; $ angular process of the dentary absent [L+01]; "reversed triangle" molar pattern (primitive); $? molar interlocking absent [L+01] (reversal -- doubtful); lower teeth: $? ultimate premolar cusp a with symmetrical outline (lateral view) [L+01]; $ ultimate premolar cingulid cuspule 'd' present (= hypoconulid?) [L+01]; $? acute trigonid angle with b/paraconid positioned more lingually [L+01]; $ b/paraconid & c/metaconid roughly equal in height [L+01]; $? well-advanced jaw rotation during the occlusion [L+01].

Note: those venturing further into mammals may wish to refer to the discussion of Molars.

References: Luo et al. (2001a) [L+01].

Phylogeny

<==Mammalia [Marsupionta, Symmetrodonta, Tribosphenida]
   |--+--Australosphenida
   |  `--Shuotherium Chow & Rich 1982 [Shuotheridia, Shuotheriidae, Yinotheria]
   |       |--*S. dongi Chow & Rich 1982
   |       |--S. kermacki Sigogneau-Russell 1998
   |       `--S. shilongi Wang et al. 1998
   `--+--Fruitafossor
      |--Volaticotherium Meng, Hu et al. 2006 [Volaticotheria, Volaticotheriidae]
      |    `--*V. antiquum Meng, Hu et al. 2006 [=V. antiquus]
      `--+--Tinodon Marsh 1879 [incl. Eurylambda Simpson 1929, Tinodontidae]
         `--+--Eutriconodonta
            `--Theriiformes
                 |--Trechnotheria
                 `--+--Multituberculata
                     `--Gondwanatheria
                           |--Lavanify
                           |--Ferugliotherium [Ferugliotheriidae]
                           |--Gondwanatherium
                           `--Sudamerica

Mammalia incertae sedis:

 Kermackia
 Hypomylos
 Asiocoryphodon
   |--A. conicus Xu 1976
   `--A. lophodontus Xu 1976
 Gobiatherium
 Hunanictis
 Advenimus hupeiensis Dawson et al. 1984
 Hohomys lii Hu 1995
 Anatolostylops dubius
 Motheretus telhebresus
 Nguruwe kijivium
 Dzungariotherium orgosense
 Alloptox minor
 Megacricetodon
   |--M. minor
   |    |--M. m. minor
   |    `--M. m. debruijni
   `--M. sinensis
 Protalactaga tunggurensis
 Sayimys obliquidens
 Dinocrocuta gigantea
 Acerorhinus
   |--A. fuguensis
   |--A. hezhengensis
   |--A. palaeosinensis
   `--A. tsaidamensis
 Pararhizomys hipparionum
 Iranotherium morgani
 Honanotherium schlosseri
 Parataxidea sinensis
 Adcrocuta variabilis
 Cervavitus novorossiae
 Euroscaptor mizura (Günter 1880)
   |--E. m. mizura
   `--E. m. ohtai (Imaizumi 1955)
 Acanthonotus Goldfuss 1809
 Hoplophoneus
   |--H. occidentalis
   `--H. primaevus
 Paraglirulus werenfelsi
 Glirudinus undosus
 Spermophilinus bredai
 Albanensia albanensis
 Euprox furcatus
 Tapiravus polkensis
 Hsiuannania maguensis
 Wanotherium xuanchengensis
 Yingabalanara Archer, Every et al. 1990 [Yingabalanaridae]
   `--*Y. richardsoni Archer, Every et al. 1990
 Pseudostoma Say 1823 [=Pseudotoma (l. c.) non Bellardi 1875]
 Spinigera Lesson 1842
 Nothodectes gidleyi Matthew 1917
 Picrodus silberlingi Douglass 1908
 Megopterna minuta Douglass 1908
 Cuscus
   |--C. brevicaudatus
   `--C. maculatus [incl. C. m. var. ochropus]
 Ericulus spinosus

* Type species of generic name indicated

References

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Burton, J. A., & V. G. Burton. 1987. Collins Guide to the Rare Mammals of the World. Collins: London.

Cifelli, R. L., & S. K. Madsen. 1999. Spalacotheriid symmetrodonts (Mammalia) from the medial Cretaceous (upper Albian or lower Cenomanian) Mussentuchit local fauna, Cedar Mountain Formation, Utah, USA. Geodiversitas 21 (2): 167-214.

Crawford, R. L. 1992. Catalogue of the genera and type species of the harvestman superfamily Phalangioidea (Arachnida). Burke Museum Contributions in Anthropology and Natural History 8: 1-60.

Deng T., Wang X., Ni X. & Liu L. 2004. Sequence of the Cenozoic mammalian faunas of the Linxia Basin in Gansu, China. Acta Geologica Sinica (English Edition) 78 (1): 8-14.

Gray, J. E. 1866. Notes on some Mammalia from Port Albany (Cape York Peninsula), North Australia, with the descriptions of some new species. Proceedings of the Zoological Society of London 1866: 219-221.

Huang X. & Chen L. 1997. Mammalian remains from the Late Paleocene of Guichi, Anhui. Vertebrata PalAsiatica 35 (1): 49-67.

Huang W., R. Ciochon, Gu Y., R. Larick, Fang Q., H. Schwarcz, C. Yonge, J. de Vos & W. Rink. 1995. Early Homo and associated artefacts from Asia. Nature 378: 275-278.

Iwahashi, J. (ed.) 1992. Reddo Deeta Animarusu: a pictorial of Japanese fauna facing extinction. JICC: Tokyo.

Kielan-Jaworowska, Z., R. L. Cifelli & Z.-X. Luo. 2002. Dentition and relationships of the Jurassic mammal Shuotherium. Acta Palaeontologica Polonica 47 (3): 479-486.

Kielan-Jaworowska, Z., & J. H. Hurum. 2001. Phylogeny and systematics of multituberculate mammals. Palaeontology 44 (3): 389-429.

Long, J., M. Archer, T. Flannery & S. Hand. 2002. Prehistoric Mammals of Australia and New Guinea: One Hundred Million Years of Evolution. University of New South Wales Press: Sydney.

Luo, Z.-X., P. Chen, G. Li & M. Chen. 2007. A new eutriconodont mammal and evolutionary development in early mammals. Nature 446: 288-293.

Luo, Z.-X., R. L. Cifelli & Z. Kielan-Jaworowska. 2001. Dual origin of tribosphenic mammals. Nature 409: 53-57.

Luo, Z.-X., Z. Kielan-Jaworowska & R. L. Cifelli. 2002. In quest for a phylogeny of Mesozoic mammals. Acta Palaeontologica Polonica 47: 1-78.

Moyà-Solà, S., M. Köhler, D. M. Alba, I. Casanovas-Vilar & J. Galindo. 2004. Pierolapithecus catalaunicus, a new Middle Miocene great ape from Spain. Science 306: 1339-1344.

Meng, J., Y. Hu & C. Li. 2003. The osteology of Rhombomylus (Mammalia, Glires): Implications for phylogeny and evolution of Glires. Bulletin of the American Museum of Natural History 275: 1-247.

Meng, J., Y. Hu, Y. Wang, X. Wang & C. Li. 2006. A Mesozoic gliding mammal from northeast China. Nature 444 (7121): 889-893.

Meng, J., Y. Hu, Y. Wang, X. Wang & C. Li. 2007. Corrigendum: A Mesozoic gliding mammal from northeastern China. Nature 446: 102.

Packer, J. B., & T. E. Lee, Jr. 2007. Neusticomys monticolus. Mammalian Species 805: 1-3.

Pickford, M. 2002. Early Miocene grassland ecosystem at Bukwa, Mount Elgon, Uganda. Comptes Rendus Palevol 1: 213-219.

Schlegel, H. 1866. Communication from, on mammals and birds collected in Madagascar. Proceedings of the Zoological Society of London 1866: 419-426.

Simpson, G. G. 1935a. The Tiffany fauna, Upper Paleocene. I.–Multituberculata, Marsupialia, Insectivora, and ?Chiroptera. American Museum Novitates 795: 1-19.

Simpson, G. G. 1935b. New Paleocene mammals from the Fort Union of Montana. Proceedings of the United States National Museum 83 (2981): 221-244.

Valkenburgh, B. van. 1991. Iterative evolution of hypercarnivory in canids (Mammalia: Carnivora): evolutionary interactions among sympatric predators. Paleobiology 17 (4): 340-362.

Wallace, S. C., & X. Wang. 2004. Two new carnivores from an unusual late Tertiary forest biota in eastern North America. Nature 431: 556-559.

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Credits

Introductory paragraph ATW020407, characters ATW001202, descriptions ATW040806; phylogeny Christopher 09:37, 14 August 2009 (UTC).