Wiehenvenator

Wiehenvenatoris agenusofmegalosauridtheropoddinosaurfrom theMiddle Jurassic(Callovian) of north westernGermany.The genus contains a single species,W. albati.

Wiehenvenator Temporal range:Callovian ~
Remains of the skull
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Clade:	Dinosauria
Clade:	Saurischia
Clade:	Theropoda
Family:	†Megalosauridae
Subfamily:	†Megalosaurinae
Genus:	†Wiehenvenator Rauhutet al,2016
Type species
†Wiehenvenator albati Rauhutet al,2016

Discovery and naming

Landscape of theWiehen Hills,whereWiehenvenatorremains have been found

In 1998, geologist Friedrich Albat, prospecting for the Landschaftsverband Westfalen-Lippe Museum of Natural History, discovered the remains of a large theropod at the abandoned Pott quarry in theWiehen HillsnearMinden,Westphalia.The remains were discovered within theOrnatenton Formation,a geological formation composed mainly ofmudstone,sandstones,and a horizon of carbonateconcretions.The fragmentary theropod skeleton, found alongside abundant marine invertebrates and fossilized wood, was excavated between October 1998 and October 2001. At the time of their discovery, the bones were heavily weathered out of the surrounding sediments and are somewhat poorly preserved. The numerous breaks and cracks found in the material risked being destroyed upon removal from the matrix, and so led the excavation team to instead extract them into jackets that were then later prepared in the laboratories of the LWL Museum für Naturkunde.

The find received extensive press attention and was informally known asDas Monster von Minden(the Minden Monster). Reports in the German edition of theNational Geographicof a rib 50% larger than that ofAllosaurusstirred speculations that it reached 15 metres (49 ft) in length.Thomas Holtzestimated it at 12 metres (39 ft) in 2012.Other researchers concluded to smaller dimensions: Mickey Mortimer in 2003 estimated the animal to be 7 to 8 metres (23 to 26 ft) in length and 0.75 to 1.2 metric tons (0.83 to 1.32 short tons) in weight.

In 2015, it was announced that the find had been identified as a new species ofmegalosaurid.In 2016, the fossils were named and described as thetype speciesWiehenvenator albatiby Oliver W. M. Rauhut, Tom R. Hübner and Klaus-Peter Lanser. The generic name combines a reference to theWiehengebirge,the German name of the Wiehen Hills, with aLatinvenator( "hunter" ). Thespecific namehonours Friedrich Albat, the discoverer. As the name was published in anelectronic publication,Life Science Identifierswere needed for its validity. These were 95638CFF-5618-4D31-9086-D821F6EE6B39 for the genus and 262FA776-9ABC-4565-9A17-931CB4BEFBFC for the species.

Amegalosauroidpedal phalanx ((WMNM P27698, P27693) from the Ornatenton Formation discovered in two parts during October 1999 and April 2000 may have belonged to the holotype ofW. albati.

Description

Restoration based onTorvosaurus,a close relative

Thetype specimenofWiehenvenatorconsists of an assortment of bones found in theOrnatenton Formationdating from the middleCallovian.They include parts of the skull (rightpremaxilla,rightmaxilla,rightlacrimal bone,rightpostorbitaland possible front branch of the right quadratojugal), theanteriorparts of a right lower jaw (dentary), six teeth, three tail vertebrae, a pair of fused median segments of reargastralia,one complete rib and four rib fragments, a finger phalanx, bothfibulae,a right astragalus and a right calcaneum. All these bones were seen as belonging to a single individual. Two additional tailvertebraemay also belong to it. Histological analysis of its fibulae suggests that the holotype ofWiehenvenator albatiwas at least in its ninth year of life, however, the age at death might have been well over ten years. The remains indicated that the animal was actively growing, but narrow growth zones indicated that the skeletal growth rate was slowing down. From this it can be determined that the growth state ofWiehenvenatorwas that of a largesubadultindividual.

Size ofWiehenvenatorcompared to a human

The length ofWiehenvenatorcan be estimated by extrapolating from its maxilla, which has 82 percent of the length of the maxilla ofTorvosaurus gurneyi,itself estimated at 10 metres (33 ft). Another estimate can be gleaned from the fact that its tail vertebrae and fibulae are roughly equal in length to those ofTorvosaurus tanneri,which had been estimated at 9 metres (30 ft), thus makingWiehenvenatorone of the largest known European theropods.

Classification

In 2016,Wiehenvenatorwas placed in theMegalosauridaeas asister taxontoTorvosaurus.The following is a cladogram based on the phylogenetic analysis conducted by Rauhut et al., showing the relationships ofWiehenvenator.

Megalosauridae	Eustreptospondylus Dubreuillosaurus Magnosaurus Afrovenator Piveteausaurus Duriavenator Megalosaurus Wiehenvenator Torvosaurus

Paleoecology

Restoration ofMetriorhynchus,of which remains have been found alongsideWiehenvenator

After discovering the initial remains ofWiehenvenator,members of the excavation team returned to the site and continued to search the surroundings for further material. After searching 35m both east and west of theOrnatenton Formation,some weathered vertebral centra and teeth ofLiopleurodonwere found.One year later, in mid-October 1999, the remains consisting of a maxillary fragment, bone fragments, and a tooth, of a second theropod were found 28.5 m north-west of the first locality.On October 3, 2014, in an overgrown quarry to the west, the skull and lower jaws of the crocodylomorphMetriorhynchuswere discovered by an honorary member of the LWL Museum für Naturkunde. These multiple discoveries imply a potential for more material to be found in the future.

See also

• 2016 in paleontology

External links

• "Wiehenvenator albati, Das Monster von Minden" on Earth Archives Website
• "Paleo Profile: The Monster of Minden" at Scientific American Website