Genus: Undorosaurus EFIMOV, 1999
Etymology: From the village of Undory, Ul’yanovsk Region, European Russia, and Greek, sauros, "lizard."
= Cryopterygius DRUCKENMILLER, HURUM, KNUTSEN, & NAKREM, 2012
Etymology: Greek, cryo, "cold or frozen" and Greek, pterygius, "fin"; in reference to its distinctive paddle morhpology and its occurrence in high latitudes and excavation out of permafrost.

Species: gorodischensis EFIMOV, 1999
Etymology: From the village of Gorodishchi of the Ul’yanovsk District of Ul’yanovsk Region, European Russia, where the ichthyosaur species was first found.

Holotype: Undory Paleontological Museum (UPM), no. EP-II-20 (572)

Locality: Gorodischi, Volga Region near Ul’yanovsk, European Russia.

Horizon:

Biostratigraphy: Epivirgatites nikitini Zone.

Age: Middle Volgian (Tithonian Stage) Substage, Late Malm Epoch, Late Jurassic.

Material: Oribital, nasal, parietal and occipital region, upper and lower jaws, and teeth, humeral and pelvic girdles, isolated vertebral centra, from different regions of the vertebral column, and fore and hind limbs.

Referred material:

UPM, no. EP-II-21 (1075): Anterior part of a disarticulated skeleton including nasals, premaxillae, and occipital bones, lower jaw, humeral girdle (coracoid, scapulae, and fragmentary clavicles), forelimbs (humerus and forearm bones), and vertebral column (atlas and 18 thoracic vertebrae.

UPM, no. EP-II-22 (1073): Anterior part of a dismembered skeleton including the nasals, jaws, and occipital bones, humeral girdle (coracoids and scapulae), fore limbs (humeri and isolated phalanges), and vertebral column (17 anterior thoracic vertebrae, ribs, and isolated neural arches.

 

Locality: Gorodischi, Volga Region near Ul’yanovsk, European Russia.

Horizon:

Biostratigraphy: Craspedites subdites Zone.

Age: Middle Volgian (Tithonian Stage) Substage, Late Malm Epoch, Late Jurassic.

Material:

UPM, no. EP-II-23 (744): Jaws, occipital bones, and teeth, humeral girdle (Coracoid and scapulae), right fore limb, (radius, ulnar, and phalanges), and vertebral column (atlas, 35 vertebrae from various regions.

 

= Undorosaurus khorlovensis EFIMOV, 1999
Etymology: From the village of Khorlovo, Voskresenskii District, Moscow Region, European Russia.

Holotype: UPM, no. EP-II-27 (870)

Locality: Village of Khorlovo, Voskresenskii District, Moscow Region, European Russia.

Horizon:

Biostratigraphy: Virgatites virgatus Zone.

Age: Middle Volgian (Tithonian Stage) Substage, Late Malm Epoch, Late Jurassic.

Material: Nasals, orbitals, and jaw bones, humeral girdle (right and left scapulae and fragmentary clavicles), fore limb (right and left humeri, radius, and phalanges) 3 posterior thoracic vertebrae and proximal part of a femur.

Referred material:

UPM, no. EP-II-28 (1090): Tooth, cervical and thoracic vertebrae, one-half of the left coracoid bearing the lateral facete, fragmentary coracoid bearing the medial facet.

 

Locality: Lopatino, Moscow Region, European Russia.

Horizon:

Biostratigraphy: Virgatites viragatus Zone.

Age: Middle Volgian (Tithonian Stage) Substage, Late Malm Epoch, Late Jurassic.

Material:

UPM, no EP-II-30 (1089): Dentary.

 

= Cryopterygius kristiansenae DRUCKENMILLER, HURUM, KNUTSEN, & NAKREM, 2012
= Genus: Nova DRUCKENMILLER, HURUM, KNUTSEN & NAKREM, 2011
Etymology: In honour of Lena Kristiansen, long-time participant in the Spitsbergen Jurassic Research Group field work on Spitsbergen.

Holotype: PMO 214.578.

Locality: North side of Janusfjellet, approximately 13 km northeast of Longyearbyen, Arctic Archipelago of Svalbard, Norway.

Horizon: 6.2 meters below the Dorsoplanites Bed, Slottsmøya Member, Agardhfjellet Formation.

Biostratigraphy: Dorsoplanites ilovaiskyi to Dorsoplanites maximus ammonite zone.

Age: Middle Volgian (Tithonian Stage), Upper Malm Epoch, Upper Late Jurassic.

Material: Complete skull, the entire presacral and preflexural vertebral column, numerous ribs and gastralia, most of the right and left pectoral girdle and limb, and the left pelvic girdle and hind limb.

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Species: bogoljubovi EFIMOV, 1997
Etymology:

Holotype:

Horizon:

Biostratigraphy:

Age:

Material:
, spines of balistes, and teeth of sharks.

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Species: nessovi EFIMOV, 1999
Etymology: In memory of paleontologist L. A. Nesov.

Holotype: UPM, No. EP-II-24 (785)

Locality: Zakhar’evskii Mine, Near Ul’yanovsk, Volga Region, European Russia.

Horizon:

Biostratigraphy: Virgatites virgatus Zone.

Age: Middle Volgian (Tithonian Stage) Substage, Late Malm Epoch, Late Jurassic.

Material: Occiput, and upper and lower jaws, humeral girdle, right and left coracoids, scapulae, and fragmentary clavicles, right and left fore limbs, and vertebral column (atlas + epistropheus, 15 vertebrae from varous regions), ribs and neural processes.

Referred material:

Locality: Gorodischi, Volga Region near Ul’yanovsk, European Russia.

Horizon:

Biostratigraphy: Virgatites firgatus Zone.

Age: Middle Volgian Substage, Late Jurassic.

Material:

PM, no. EP-II-25 (900): Nasals, orbitals, and dentaries, teeth, sclerotic plates, right flipper, fragmentary humeral girdle and vertebrae.

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Species: trautscholdi ARKHANGEL'SKY & ZVERKOV, 2014
Etymology: In honor of outstanding geologist H. Trautschold, who collected the remains of the descrbing specimen and made the original descrption.

Holotype: GSM 1503

Localiyt: Mnevniki, Moscow Region, European Russia.

Horizon:

Biostraigraphy:

Age: Upper Volgian Substage, Late Jurassic.

Material: Partial left forefin.

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Species: kielanae (TYBOROWSKI, 2016) ZVERKOV & EFIMOV, 2019
Etymology: In honor of Zofia Kielan-Jaworowska (1925-2015), worldrenowed Polish researher of Mesozoic Mammals.
= Cryopterygius kielanae TYBOROWSKI, 2016

Holotype: GMUL 2579-81

Locality: Owadow-Brzezinki Quarrry, of Nordkalk GmbH, Shawno, Vinicity of Tomaszow Mazowiecki,51°22'34"N, 20°08'07"86"E,  Central Poland.

Horizon: Shawno Limestone Member, Lower part of the Keynia Formation.

Biostratigraphy:

Age: Uppermost Lower Tithonian Stage = Middle Volgian, Malm Epoch, Late Jurassic.

Material: A fragment of the lower jaw, isoalted teeth, fragmetns of pterygoid and quadrate, parts of the cervical, dorsal, and caudal vertebral column, most of the left pectoral girdle, right clavicle, right forefin, and lower femur.