Palaeos:		Temnospondyli
The Vertebrates		Capitosauria

Capitosauria

TETRAPODA
|--+--LEPOSPONDYLI
|  `--REPTILIOMORPHA
|
TEMNOSPONDYLI
|--Edopoidea
`--+--Dvinosauria
   `--+--Euskelia
      `--Stereospondyli
         |--Rhinesuchidae
         `--+--Lydekkerinidae
            |--+--Plagiosauroidea
            |   `--+--Rhytidosteidae
            |       `--Brachyopoidea
             `--+--Capitosauria
                 |  `--+--Mastodonsaurus
                 |     `--Capitosauridae
                 `--Trematosauria
                    |--Trematosauroidea
                    `--+--Metoposauroidea

1. Capitosauria X
2. Capitosauridae X
3. Mastodonsaurus X

Here's another of those very important groups of ancient amphibians that unfortunately at present only have scant coverage on Palaeos. Hopefully this will be rectified at some point. It's hasrd to imagine the Triassic period without capitosaurs lurking in rivers and waterways, they are such an integral part of the early Mesozoic landscape. Despite all looking very similar, with big flat solid heads and long stocky flattened bodies, they were actually quite a diverse group, including a number of distinct families and clades. They count among their number not only more modest sized creatures but some of the biggest amphibians to have ever lived, such as the huge Mastondonsaurus giganteus, which reached 6 or more meters in length. The Capitosaurs, or Mastodonsauroidea to give them a taxonomically equivalent but phylogenetically distinct name, were, along with the Trematosauriaia, the last great evolutionary radiation of temnosopondyl evolution, surviving the rigours of Pangaean droughts, giant phytosaurs, and more. Such an important and interesting group really deserve several detailed pages to summarise their phylogenetica history. For the present however, all that we can offer are a few short technical descriptions and an under construction sign. Hopefully this will be rectified in due course. MAK111116

Descriptions

Capitosauria: 

Range: Early Triassic to Late Triassic. 

Phylogeny: Stereospondyli::: Trematosauria + *: Lydekkerinidae + (Mastodonsaurus + Capitosauridae) 

Introduction: The capitosaurs were a large and important group of large to huge flat-headed semi-aquatic or completely aquatic tetrapods.   Some forms reached three to four or even five metres in length.  They dominated the freshwater ponds, lakes and rivers of the Triassic, but were pushed to extinction by the carnivorous phytosaurs which appeared at the end of the period.  MAK

Characters: Very flat skulls, small limbs, ossification reduced (obligate aquatic); some very large forms. ATW990919.

Mastodonsaurus: Jaeger 1852;  

Range: Middle Triassic of Europe.

Phylogeny: Capitosauria:: Capitosauridae + *.

Characters: ~6m; 

Links: Mastodonsaurus; Triassico; Adventures in Etymology- Oplosaurus, Mastodonsaurus; Mastodonsaurus (Bullyland) (toy); amphibien keuper trias fossilien (most of jaw); fossil des monats trias (Best on the Web); Triassic (a bit hokey, but interesting); SITE Name- Ladram Bay to Sidmouth Parish- Sidmouth Local ...; Some Amphibian and Reptilian Remains (1859); Waldenburg Online - Bildung, Kultur & Vereine - Urweltmuseum.  ATW030621. 

Capitosauridae: Cyclotosaurus, Eryosuchus, Kestrosaurus, Paracyclotosaurus, Parotosuchus

Range: Early to Late Triassic of Russia, Australia & South Africa.

Phylogeny: Capitosauria:: Mastodonsaurus + *.

The capitosaurs were large aquatic tetrapods common throughout much of the Triassic  The various species are distinguished by relative proportions of the snout, the ornamentation or sculpting on the skull, and the degree of closure of the otic notch.

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