A partial skeleton (SDSM 78147) consists of two thoracic vertebrae, the sternum keel, the right coracoid and shoulder blade, the sternal part of the left coracoid, the right upper arm, parts of the left upper arm, the proximal right ulna, the proximal left ulna and radius (articulated), the proximal right carpometacarpus, the proximal left carpometacarpus, the distal left carpometacarpus, the synsacrum, the right and left thighs, the proximal right tibiotarsus, the right and left distal tibiotarsus, and the proximal right tarsometatarsus.
A partial skeleton (MLP 86-X-28-1) consists of three isolated teeth, part of the lower jaw with another tooth in situ, some other skull fragments, vertebrae of the neck, back, hips and tail, some shoulder and hip bones (scapula, ilium) a thigh bone (femur), foot and hand bones (five metapodials and two phalanges), and numerous pieces of armor.[17][14]
A single specimen that contains skull fragments possibly from the premaxilla, maxilla, and dentary as well as a caudal vertebra, teeth, and pedal elements, UCMP 276000.[20][23]
Santa Marta Cove, in the lower levels of the formation.[27]
MLP08-III-1-1, disarticulated and partial skeleton that includes one incomplete dorsal vertebra, three sacral centra, seven caudal vertebrae; two incomplete dorsal rib shafts, one proximal haemal arch, incomplete right scapulocoracoid, incomplete right humerus, two metacarpals, both ilia, right pubis, right ischium, right femur, right distal tibia, incomplete metatarsal III, first phalanx of pedal digit III, two phalanges of pedal digit IV, and indeterminate fragments.
SGO.PV.6579, fragmentary postcranial skeleton preserving eight fragmentary caudal centra, two articular propodial heads (likely femora), an epipodial (likely a fibula), ventral portion of the right ilium, partial left pubis, and several rib portions[28]
"MLP 11-II-20-4, one cervical vertebra preserving a partial rib; MLP 86-X-28-3, two cervical vertebrae; MLP 86-X-28-(2–6), 10 posterior cervical vertebrae articulated with three pectoral vertebrae, part of two dorsal vertebrae, ribs, and indeterminate fragments."[29]
Indeterminate
Santa Marta Cove
SGO.PV.6508, one isolated cervical vertebral centrum[28]
Indeterminate
W Santa Marta Cove
MN 7820-V, four vertebral centra and fragments of another six centra[30]
Indeterminate
Cape Lamb
MLP 98-I-10-20, an incomplete postcranial skeleton (juvenile)[31]
Indeterminate
Vega Island
SDSM 78156 (a nearly complete, articulated torso, partial paddles, and neck and tail sections)[32]
MLP 93-I-5-1, postcranial skeleton preserving a complete cervical region with 54 cervical vertebrae, three pectoral vertebrae, 17 dorsal vertebrae, three sacral vertebrae, anterior and medial caudal vertebrae, pectoral and pelvic girdles, forelimbs and hind limbs, ribs, and gastroliths.[35]
Notes Uncertain or tentative taxa are in small text; crossed out taxa are discredited.
Local Environments were similar to Modern forested areas rich in Nothofagus
During the Campanian–Maastrichtian, the Antarctic Peninsula supported temperate, humid forests dominated by podocarps, araucarian conifers, and a diversifying group of angiosperms. Key angiosperm families included Nothofagaceae, Monimiaceae, Cunoniaceae, Proteaceae, Myrtaceae, Lauraceae, Atherospermataceae, Winteraceae, and extinct Sassafras-like forms.[41][42] Another important group is Asteraceae, with Dasyphyllum-like pollen, the oldest fossils ever found for the family.[43] At The Naze area, Podocarpaceae-Nothofagus rainforests thriving in lowland areas under cool-temperate, frost-free, and high-rainfall conditions, with understories rich in other angiosperms and ferns.[44] Smaller components, likely endemic, included lycophytes, bryophytes, Proteaceae, Liliaceae, Palmae or Microthyriaceae, and various herbaceous or shrubby dicotyledons.[44] Forests were structurally similar to modern Valdivian temperate forests. These plants were primarily found in riparian floodplains, with bryophyte-lycophyte rich swamps and Chlorophyta-rich lake margins, while influence of marine waters can be seen by Dinoflagellates. The climate was highly humid and seasonal, as evidenced by distinct growth rings in Agathoxylon fossil wood from Lachman Crags and The Naze, indicating a temperate but variable environment.[44] The flora reflects a transition from gymnosperm-dominated to mixed angiosperm-conifer ecosystems under polar greenhouse conditions.[41][44]
↑ di Pasquo, M.; Martin, J.E. (2013). "Palynoassemblages Associated with a Theropod Dinosaur from the Snow Hill Island Formation (lower Maastrichtian) at the Naze, James Ross Island, Antarctica". Cretaceous Research. 45: 135–154. Bibcode:2013CrRes..45..135D. doi:10.1016/j.cretres.2013.07.008. hdl:11336/80121.
1 2 3 4 5 6 7 8 9 Kriwet, J.; Lirio, J. M.; Nuñez, H. J.; Puceat, E.; Lécuyer, C. (2006-01-01), Francis, J. E.; Pirrie, D.; Crame, J. A. (eds.), "Late Cretaceous Antarctic fish diversity", Cretaceous–Tertiary High-Latitude Palaeoenvironments: James Ross Basin, Antarctica, vol.258, Geological Society of London, p.0, ISBN978-1-86239-197-0, retrieved 2025-05-13
1 2 Gouiric-Cavalli, Soledad; Cabrera, Daniel A.; Cione, Alberto L.; O'Gorman, José P.; Coria, Rodolfo A.; Fernández, Marta (2015-09-03). "The first record of the chimaeroid genus Edaphodon (Chondrichthyes, Holocephali) from Antarctica (Snow Hill Island Formation, Late Cretaceous, James Ross Island)". Journal of Vertebrate Paleontology. 35 (5): e981128. Bibcode:2015JVPal..35E1128G. doi:10.1080/02724634.2015.981128. hdl:11336/53488. ISSN0272-4634. S2CID129091192.{{cite journal}}: CS1 maint: article number as page number (link)
↑ Fernando E. Novas; Marta S. Fernandez; Zulma B. de Gasparini; Juan M. Lirio; Héctor J. Nuñez; Pablo Puerta (2002). "Lakumasaurus antarcticus, n. gen. et sp., a new mosasaur (Reptilia, Squamata) from the Upper Cretaceous of Antarctica". Ameghiniana. 39 (2): 245–249. hdl:11336/136746. S2CID 128304133.
D. Néraudeau, A. Crame, and M. Kooser. 2000. Upper Cretaceous echinoids from James Ross Basin, Antarctica. Géobios 33(4):455–466 doi:10.1016/S0016-6995(00)80079-0
R. A. Otero, S. Soto-Acuna, A. O. Vargas, D. Rubilar Rogers, R. E. Yury Yanez and C. S. Gutstein. 2013. Additions to the diversity of elasmosaurid plesiosaurs from the Upper Cretaceous of Antarctica. Gondwana Research doi:10.1016/j.gr.2013.07.016
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