Hubbry Logo
ShastasaurusShastasaurusMain
Open search
Shastasaurus
Community hub
Shastasaurus
logo
8 pages, 0 posts
0 subscribers
Be the first to start a discussion here.
Be the first to start a discussion here.
Shastasaurus
Shastasaurus
Shastasaurus
View on Wikipedia
from Wikipedia

Shastasaurus
Temporal range: Late Triassic, 235.0–205.6 Ma[1]
Partial skull of Shastasaurus pacificus (UCMP 9017)
Scientific classification Edit this classification
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: †Ichthyosauria
Suborder: †Longipinnati
Node: †Merriamosauria
Family: †Shastasauridae
Merriam, 1895
Genus: †Shastasaurus
Merriam, 1895
Type species
†Shastasaurus pacificus
Merriam, 1895
Species

†S. pacificus
Merriam, 1895
†S.? liangae
(Yin et al., 2000 [originally Guanlingsaurus])
†S.? sikanniensis
(Nicholls & Manabe, 2004 [originally Shonisaurus])

Synonyms
  • ?Guanlingsaurus Yin et al., 2000

Shastasaurus ("Mount Shasta lizard") is an extinct genus of ichthyosaur from the Late Triassic.[2] Specimens have been found in the United States, Canada, and China.[3]

Description

[edit]
Size of Shonisaurus popularis (green) and S. sikanniensis (red), a possible species of Shastasaurus, compared with a human

Shastasaurus lived during the late Triassic period. The type species, S. pacificus, is known from California, with the name Shastasaurus directly referencing Shasta County, Northern California, where the type specimen was found.[4] S. pacificus was a medium-sized ichthyosaur, measuring over 7 metres (23 ft) in length.[5] A second possible species of Shastasaurus, S. sikanniensis, is known from the Pardonet Formation British Columbia, dating to the middle Norian age (about 210 million years ago).[6] By comparison, S. sikanniensis was one of the largest known ichthyosaurs, similar in size to modern-day cetaceans, measuring up to 21 metres (69 ft) in length and weighing 81.5 metric tons (89.8 short tons).[7]

Shastasaurus was highly specialized, and differed considerably from other ichthyosaurs. It was very slender in profile. S. sikanniensis had a ribcage slightly less than 2 metres (6.6 ft) deep despite a distance of over 7 metres (23 ft) between its flippers.[6] With its unusually short, toothless snout (compared to the longer, toothed, dolphin-like snouts of most ichthyosaurs), it had been proposed that Shastasaurus was a suction feeder (or filled a similar ecological niche as extant beaked whales), preying primarily on soft-bodied cephalopods.[8] However, current research indicates that the jaws of shastasaurid ichthyosaurs do not fit the suction-feeding profile, since their short and narrow hyoid bones are unsuitable to withstand impact forces for such kind of feeding,[9] and since some species like Shonisaurus had robust sectorial teeth with gut contents of mollusk shells and vertebrates.[10][11]

It is unknown whether Shastasaurus had a dorsal fin; however, the smaller, more basal ichthyosaur Mixosaurus had one.[12] The upper fluke of the tail was probably much less-developed than the shark-like tails found in later species.[13]

Species and synonyms

[edit]
Restoration of S. pacificus

The type species of Shastasaurus is S. pacificus, from the late Carnian of northern California. It is known only from fragmentary remains, which have led to the assumption that it was a 'normal' ichthyosaur in terms of proportions, especially skull proportions. Several species of long-snouted ichthyosaur were referred to Shastasaurus based on this misinterpretation, but are now placed in other genera (including Callawayia and Guizhouichthyosaurus).[8] Elizabeth Nicholls and Makoto Manabe considered this species as a nomen dubium in 2000.[14]

S. sikanniensis specimen, Royal Tyrrell Museum

Shastasaurus may include a second species, Shastasaurus liangae. It is known from several good specimens, and was originally placed in the separate genus Guanlingsaurus. Complete skulls show that it had an unusual short and toothless snout. S. pacificus probably also had a short snout, although its skull is incompletely known.[8] However, a new juvenile specimen discovered in 2013 shows that the hyoid bone of Guanlingsaurus is much shorter, and considered it as a distinct genus based on phylogenetic analysis.[15]

S. sikanniensis was originally described in 2004 as a large species of Shonisaurus. However, this classification was not based on any phylogenetic analysis, and the authors also noted similarities with Shastasaurus. The first study testing its relationships, in 2011, supported the hypothesis that it was indeed more closely related to Shastasaurus than to Shonisaurus, and it was reclassified as Shastasaurus sikanniensis.[8] However, a 2013 analysis supported the original classification, finding it more closely related to Shonisaurus than to Shastasaurus.[15] In the 2019 study, S. sikanniensis was pertained within the genus Shastasaurus.[16] In the 2021 analysis, S. sikanniensis forms a clade with Shonisaurus, indicating that it is closer to Shonisaurus than to Shastasaurus.[17] Specimens belonging to S. sikanniensis have been found in the Pardonet Formation British Columbia, dating to the middle Norian age.[6]

In 2009, Shang & Li reclassified the species Guizhouichthyosaurus tangae as Shastasaurus tangae. However, later analysis showed that Guizhouichthyosaurus was in fact closer to more advanced ichthyosaurs, and so cannot be considered a species of Shastasaurus.[8]

Dubious species that were referred to this genus include S. carinthiacus (Huene, 1925) from the Austrian Alps and S. neubigi (Sander, 1997) from the German Muschelkalk.[3] S. neubigi, however, was re-described and reassigned to its own genus, Phantomosaurus.[18]

Synonyms of S. / G. liangae:
Guanlingichthyosaurus[19] liangae Wang et al., 2008 (lapsus calami)

Synonyms of S. pacificus:
Shastasaurus alexandrae Merriam, 1902
Shastasaurus osmonti Merriam, 1902

See also

[edit]

References

[edit]
Revisions and contributorsEdit on WikipediaRead on Wikipedia

Shastasaurus

View on Grokipedia
from Grokipedia
Shastasaurus is an extinct of large to gigantic ichthyosaurs that lived during the period, from the to the stages approximately 237 to 210 million years ago. Known primarily from western and eastern , this genus includes some of the largest marine reptiles ever discovered, with species reaching lengths of up to 21 meters and body masses exceeding 80 metric tons. Notable features of Shastasaurus include a high vertebral count, slender build, and in several species, a shortened rostrum with toothless jaws adapted for suction feeding on soft-bodied prey such as cephalopods. The genus was first described by American paleontologist John C. Merriam in 1895, based on fragmentary remains from , including vertebrae and limb elements of the type species Shastasaurus pacificus. Subsequent discoveries have expanded the known distribution and diversity, with valid species including S. altispinus from the Upper Antimonio Formation in northwestern , S. liangae from the Xiaowa Formation in Province, , and possibly S. sikanniensis (originally described as Shonisaurus sikanniensis) from the Pardonet Formation in , . A partial skeleton of the related ichthyosaur Callawayia neoscapularis from Williston Lake, , , represents one of the most complete specimens in , revealing advanced cranial features such as a large orbit and a resembling those of later ichthyosaurs. Many early named species, however, are considered nomina dubia due to insufficient diagnostic material, highlighting ongoing taxonomic revisions within the family. Ongoing phylogenetic studies continue to refine the classification of species within the genus. Anatomically, Shastasaurus species exhibit a range of adaptations reflecting their predatory lifestyle in ancient epicontinental seas. The Chinese species S. liangae, for instance, possesses a notably small comprising less than 10% of its 8.3-meter body length, 86 presacral vertebrae, and over 110 caudal vertebrae, supporting a streamlined form for efficient . While some species like S. altispinus retained conical teeth for grasping prey, others such as S. liangae and S. sikanniensis evolved edentulous jaws, enabling rapid jaw closure to create for capturing elusive, soft prey— a specialization that parallels the feeding mechanisms of modern toothed whales. Fossil evidence suggests Shastasaurus occupied diverse niches across the , contributing to the diversification of ichthyosaurs following the Permian-Triassic . Their enormous size underscores rapid evolutionary trends toward in marine reptiles, with S. sikanniensis exemplifying the upper limits of body size in this clade.

Discovery and naming

Initial discovery

The first specimens of Shastasaurus were discovered in the spring of 1895 in the Hosselkus Limestone of , along a ridge between Squaw Creek and . These fossils were found by James Perrin Smith of , who sent the remains to paleontologist John C. Merriam at the . Merriam identified the bones as belonging to a large reptile similar to known ichthyosaurs but of unprecedented size, and he formally described and named the genus Shastasaurus pacificus later that year based on these fragmentary postcranial elements, including vertebrae and ribs, which formed the type specimen. The Hosselkus Limestone dates to the late stage of the , approximately 235 million years ago. Merriam's initial description spurred further expeditions, leading to additional partial skeletons and skulls of Shastasaurus from sites in California and nearby Nevada during the late 19th and early 20th centuries. These early finds provided the basis for preliminary reconstructions of the animal as an enormous , though the fragmentary nature of the material limited detailed anatomical understanding at the time. Subsequent discoveries expanded the known range of Shastasaurus beyond the . In 1997, a large, nearly complete skeleton was unearthed from the Pardonet Formation in northeastern , , representing the of what was initially described as Shonisaurus sikanniensis in 2004 but later reassigned to Shastasaurus sikanniensis (though this classification remains debated in recent phylogenetic analyses). Further specimens have been reported from the Xiaowa Formation in Province, , including articulated skeletons attributed to Shastasaurus liangae, originally described under the genus Guanlingsaurus in 2000.

Etymology and historical research

The genus name Shastasaurus was established by American paleontologist John C. Merriam in 1895, combining "Shasta," in reference to Shasta County in northern California near the discovery site and close to Mount Shasta, with the Greek saurus (lizard). Merriam's foundational work continued with his 1905 monograph, which detailed skeletal elements from multiple specimens, solidifying the genus's diagnostic traits such as robust vertebral centra and limb proportions, and establishing Shastasaurus as a key representative of Late Triassic ichthyosaurs. Throughout the 20th century, researchers revised interpretations of Shastasaurus, with Alfred Sherwood Romer's 1966 synthesis in Vertebrate Paleontology integrating it into broader ichthyosaur phylogeny, emphasizing its primitive features within the group and distinguishing it from more derived forms. A notable contribution came from Elizabeth L. Nicholls and Makoto Manabe in 2001, who designated the type species S. pacificus a nomen dubium due to the holotype's fragmentary nature and lack of distinguishing characters, prompting reevaluation of generic validity. Early 20th-century reconstructions often portrayed Shastasaurus with an elongated akin to other ichthyosaurs, but this misconception was overturned by studies in the employing CT scans and on well-preserved skulls, which demonstrated a notably short, toothless rostrum adapted for feeding on soft-bodied prey like cephalopods. These advancements, building on Merriam's initial framework, have refined understandings of Shastasaurus's anatomy and , highlighting its role in diversification.

Taxonomy and classification

Higher classification

Shastasaurus belongs to the superorder , a group of extinct marine reptiles that evolved from terrestrial ancestors during the and achieved high levels of aquatic adaptation. Within , it is classified in the order and the family , which comprises early-diverging ichthyosaurs primarily known from the period. is characterized by its members' enormous body sizes, often exceeding 10 meters in length, and represents one of the earliest radiations of large-bodied ichthyosaurs in marine ecosystems. Phylogenetic analyses position Shastasaurus as one of the most basal genera within , emerging in the early ( stage, approximately 237–227 million years ago). A 2011 cladistic study by Motani et al., based on a modified of cranial and postcranial characters, recovered Shastasaurus as basal within the clade Merriamosauria, with primitive features such as a shortened rostrum and reduced adapted for feeding. This contrasts with more derived post-Triassic ichthyosaurs, such as those in the family Ophthalmosauridae (e.g., from the and ), which exhibit elongated snouts, sharper teeth, and enhanced streamlining for faster swimming. Subsequent revisions, including a 2021 phylogenetic analysis by Bindellini et al. incorporating updated character matrices from specimens, reinforce Shastasaurus's basal position but suggest a closer relationship to within , forming a monophyletic defined by shared synapomorphies like abbreviated snouts and high vertebral counts. These primitive traits, including large overall size and a relatively short, robust compared to the longer-snouted Mixosauridae (an earlier, smaller-bodied family), highlight Shastasaurus's role in the initial diversification of giant predators during the recovery from the Permian-Triassic extinction.

Species and synonyms

The type species of the genus Shastasaurus is S. pacificus, established by Merriam (1895) based on fragmentary skeletal elements, including vertebrae and limb bones, collected from the Upper Hosselkus Limestone in . Due to the holotype's incompleteness and lack of diagnostic features, Nicholls and Manabe (2001) classified it as a , which has contributed to taxonomic instability within the genus as no other species can be definitively referred without a valid type. S. alexandrae, described by Merriam (1902) based on a partial skull and vertebrae from the same locality, is considered a valid distinct from S. pacificus. S. osmonti, also from Merriam (1902) and represented by isolated postcranial elements from the same formation, is regarded as a junior of S. alexandrae due to overlapping morphology and stratigraphic equivalence. Other early names applied to North American ichthyosaur remains later attributed to Shastasaurus include the obsolete Delphinosaurus (Merriam, 1905) and Perrinosaurus, which encompassed nondiagnostic bones now recognized as belonging to various shastasaurids.
SpeciesOriginal DescriptionStatus and NotesSource
S. pacificusMerriam, 1895 (holotype: UCMP 9273, fragmentary vertebrae and limbs, Hosselkus , )Type species; nomen dubium due to inadequate Merriam (1895); Nicholls & Manabe (2001)
S. alexandraeMerriam, 1902 (holotype: partial and vertebrae, Hosselkus , )Valid species; distinguished by cranial featuresMerriam (1902); Maisey (2018)
S. altispinusCamp, 1989 (holotype: LACM 3920, vertebrae and neural spines, Antimonio Formation, , )Valid species; notable for tall neural spinesCamp (1989); López-Arellano (2016)
S.? liangaeYin et al., 2000 (as Guanlingsaurus liangae; holotype: GMPKU P1301, near-complete , Xiaowa Formation, , )Questionably valid; synonymized with Shastasaurus based on shared short rostrum, edentulous jaws, and vertebral proportionsYin et al. (2000); Motani et al. (2011)
S.? sikanniensisNicholls & Manabe, 2004 (as Shonisaurus sikanniensis; holotype: LACM 128319, nearly complete , Pardonet Formation, , )Questionably valid; transferred to Shastasaurus in phylogenetic analyses but subject to debateNicholls & Manabe (2004); Motani et al. (2011)
The taxonomic status of S.? liangae remains provisional, as its referral relies on comparisons to the dubious type material of S. pacificus, with some researchers questioning whether it warrants generic distinction given its unique combination of edentulism and body proportions. Similarly, S.? sikanniensis has sparked controversy; although Motani et al. (2011) supported its inclusion in Shastasaurus via cladistic analysis emphasizing cranial and axial similarities, the limited comparative material for S. pacificus has led to ongoing instability, with a 2021 phylogenetic study proposing it forms a distinct clade separate from Shonisaurus but still aligning closely with shastasaurid morphology.

Description

Size and proportions

Shastasaurus species exhibited significant variation in body size, with S. pacificus estimated at 7–9 meters in total length based on fossil material from . The species S. sikanniensis, known from , represents one of the largest known ichthyosaurs, reaching up to 21 meters in length. Similarly, S.? liangae from attained approximately 9 meters, as evidenced by an adult specimen measuring 8.3 meters. The body plan of Shastasaurus featured an elongated torso adapted for sustained cruising in open marine environments, with a notably short and slender comprising less than 15% of total body length—around 8.3% in S. liangae. Eyes were large relative to other ichthyosaurs, aiding vision in deep-water habitats, while foreflippers were broad but reduced in , with humeri measuring about 1% of body length in S. liangae; in the largest like S. sikanniensis, flipper spans could reach up to 4 meters. Mass estimates for S. sikanniensis derive from volumetric modeling of skeletal reconstructions, yielding approximately 81.5 metric tons, underscoring its massive scale among marine reptiles. Smaller species like S. pacificus likely weighed around 1.5 metric tons. Compared to contemporaries such as Cymbospondylus (over 17 ), Shastasaurus species, particularly S. sikanniensis, achieved greater overall dimensions, with a streamlined form prioritizing endurance over burst speed in predation.

Skull and dentition

The of Shastasaurus is characterized by a greatly abbreviated rostrum that comprises less than one-third of the total length, a feature particularly evident in specimens of S. liangae where the tapers rapidly to a point without any dental groove in the , , or dentary. This short, slender contrasts with the elongated rostra of most other ichthyosaurs and contributes to the overall reduced size, which measures approximately 8.3% of total body length in adults of S. liangae. The external nares are positioned more posteriorly than in typical ichthyosaurs, further emphasizing the compact cranial morphology. Dentition in Shastasaurus is notably reduced, with adults exhibiting an edentulous condition across species; for instance, the snout of S. liangae is completely toothless, lacking any evidence of sockets or vestigial remnants. In S. sikanniensis, teeth are present only in small juvenile individuals, set in shallow sockets, but are absent in larger specimens, suggesting a loss of dentition with ontogenetic development. Similarly, preserved portions of the maxilla and dentary in S. alexandrae show no teeth, supporting the interpretation of toothlessness as a generic trait among adults. Sensory adaptations are prominent in the cranial structure, with large orbits indicating enhanced visual capabilities suited for low-light marine environments. Although sclerotic rings are not fully preserved in most Shastasaurus specimens, the expansive orbital openings in S. liangae suggest eyes adapted for deep-water hunting, consistent with patterns observed in other shastasaurids. Species variations include primitive ichthyosaur traits in S.? liangae, such as unfused prefrontal and postfrontal bones, visible along their suture in well-preserved juvenile skulls. This unfused condition represents a plesiomorphic feature not seen in more derived ichthyosaurs.

Postcranial skeleton

The postcranial skeleton of Shastasaurus consists of an elongated and modified appendicular elements adapted for and stability in marine environments. The vertebral column is notably long, with presacral counts exceeding 60 in most species and reaching up to 86 in S. liangae, while caudal vertebrae number over 110, contributing to the genus's streamlined, body plan. Vertebral centra are generally disc-like and amphicoelous, with the cervical and dorsal regions showing increasing height and width posteriorly. Ribs in Shastasaurus are robust and form a strong, interlocking body wall that enclosed the viscera and maintained structural integrity during movement. are double-headed and relatively short, transitioning to single-headed, elongate trunk ribs in the dorsal region; these mid-trunk ribs maintain consistent length before tapering posteriorly, with grooves on their posterior surfaces for muscle attachment. The pectoral features large, rounded coracoids that are proximally broad and distally narrowed, paired with fan-shaped scapulae and slender, curved clavicles, providing robust support for the foreflippers. In contrast, the pelvic is reduced, with a bar-like ilium, broad pubis featuring an obturator notch, and a convex , reflecting diminished support typical of fully aquatic ichthyosaurs. The limbs are transformed into four paddle-like flippers, with the forelimbs significantly larger than the hindlimbs to facilitate and maneuverability. Each flipper retains four digits and exhibits hyperphalangy, with extra phalanges increasing the surface area for hydrodynamic lift; the is short and robust with an anterior notch, the is quadrangular and larger than the slender , and the is heavy with a prominent ridge. Distal elements are poorly ossified in some specimens, suggesting extensive cartilaginous support. Caudal vertebrae in the post-flexural region narrow and elongate, inferring a streamlined fluke that generated via lateral oscillations, a key for sustained cruising in open water.

Distribution and paleoecology

Geographic distribution

Fossils of Shastasaurus are known exclusively from Late Triassic deposits in North America and Asia, with no records extending into the Jurassic period. The genus is primarily documented from the lower Carnian to middle Norian stages, approximately 237 to 227 million years ago. In North America, the majority of specimens originate from western regions of the United States, Mexico, and Canada. The type locality for S. pacificus is the Hosselkus Limestone in northern California, USA, where multiple partial skeletons and skulls have been recovered from this Carnian-aged formation. In Mexico, S. altispinus is recorded from the Antimonio Formation in northwestern Sonora, with new specimens confirming its presence in Carnian-Norian strata. Farther north, S. sikanniensis and S. neoscapularis derive from the Pardonet Formation in British Columbia, Canada, dated to the middle Norian. The sole Asian occurrence is in , where S. liangae (formerly Guizhouichthyosaurus liangae) was found in the Xiaowa Formation of Province, corresponding to the lower . These fossils are preserved in marine sedimentary rocks, including micritic , , and shales, deposited within epicontinental seas that covered parts of the western Pangaean margin during the , ranging from platform margins to basinal settings. The Hosselkus , for instance, represents slope to platform margin environments with carbonate deposition, while the Pardonet and Xiaowa formations include shales indicative of offshore to pelagic marine settings.

Habitat, behavior, and diet

Shastasaurus inhabited the open marine (pelagic to outer shelf) environments of the Panthalassic Ocean, spanning the early to middle stages approximately 237–227 million years ago. Fossil-bearing formations, such as the Hosselkus in and the Xiaowa Formation in Guizhou Province, , represent outer shelf to basinal depositional settings rich in associated fauna including ammonites and halobiid bivalves, which further indicate a tropical, low-diversity marine paleoecology. As a fully aquatic , Shastasaurus was an air-breathing surface swimmer that periodically ascended to breathe, similar to modern cetaceans. It is inferred to have been viviparous, with occurring internally like other ichthyosaurs, a reproductive strategy that evolved early in the group's history to facilitate a fully marine . Evidence from closely related shastasaurs, such as multiple adult skeletons preserved in close proximity within the Luning Formation of , suggests grouping , possibly philopatric aggregations linked to over extended timescales. Several species of Shastasaurus, such as S. liangae and S. sikanniensis, were specialized suction feeders, employing a reduced, toothless and enlarged hyoid apparatus to generate rapid inflow for capturing elusive prey. Its diet primarily consisted of soft-bodied s, such as unshelled squid-like forms, and small fish, as inferred from cranial adaptations and supported by gut contents in related shastasaurs including fish bones and cephalopod remains. Locomotion in Shastasaurus relied on powerful tail-fin propulsion for efficient forward thrust, with small, poorly ossified flippers providing stabilization and minimal drag during cruising. Its elongate body, featuring a high vertebral count exceeding 110 caudals, facilitated sustained in open waters, though specific speed estimates remain limited; general ichthyosaur models suggest cruising velocities around 1–5 km/h for similar forms.

References

  1. https://pmc.ncbi.nlm.nih.gov/articles/PMC3100301/
  2. https://www.cambridge.org/core/journals/journal-of-paleontology/article/shastasaurus-altispinus-ichthyosauria-shastasauridae-from-the-upper-triassic-of-the-el-antimonio-district-northwestern-sonora-mexico/8941B431C7532F1689A6A5535E08E0D8
  3. https://www.tandfonline.com/doi/abs/10.1080/02724634.1994.10011550
  4. https://ucmp.berkeley.edu/about-ucmp/history-of-ucmp/1901-shasta-county-expedition/
  5. https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0019480
  6. https://www.tandfonline.com/doi/abs/10.1080/02724634.1999.10011160
  7. https://doi.org/10.7717/peerj.11179
  8. https://www.schweizerbart.de/papers/njgpa/detail/217/89352/Observations_on_Triassic_ichthyosaurs_Part_VI_On_the_cranial_osteology_of_Shastasaurus_alexandrae_MERRIAM_1902_from_the_Hosselkus_Limestone_Carnian_Late_Triassic_of_Northern_California_with_a_revision_of_the_genus
  9. https://www.tandfonline.com/doi/abs/10.1671/0272-4634(2004)024[0838:GIOTTN]2.0.CO;2
  10. https://www.science.org/doi/10.1126/science.abf5787
  11. https://www.researchgate.net/publication/260287166_Observations_on_Triassic_ichthyosaurs_Part_VI_On_the_cranial_osteology_of_Shastasaurus_alexandrae_MERRIAM_1902_from_the_Hosselkus_Limestone_Carnian_Late_Triassic_of_Northern_California_with_a_revision
  12. http://www.ivpp.cas.cn/cbw/gjzdwxb/xbwzxz/200909/P020090917531791680790.pdf
  13. https://doi.org/10.1371/journal.pone.0019480
  14. https://pubs.geoscienceworld.org/books/book/chapter-pdf/3733445/9780813754550_ch08.pdf
  15. https://www.sciencedirect.com/science/article/pii/S1002007108002530
  16. https://pmc.ncbi.nlm.nih.gov/articles/PMC3960099/
  17. https://www.researchgate.net/publication/260214224_Terrestrial_Origin_of_Viviparity_in_Mesozoic_Marine_Reptiles_Indicated_by_Early_Triassic_Embryonic_Fossils
  18. https://www.cell.com/current-biology/fulltext/S0960-9822(22)01761-4
  19. http://faculty.cortland.edu/paleo-lab/wp-content/uploads/sites/39/2019/04/Druckenmiller_etal_2014.pdf
  20. https://royalsocietypublishing.org/doi/10.1098/rspb.2018.2786
Add your contribution
Related Hubs
User Avatar
No comments yet.