banner



Home  ›  What Was The First Animal To Walk On Land

What Was The First Animal To Walk On Land

Written By Thursday, May 12, 2022 Add Comment Edit

Genus of extinct sarcopterygian (lobe-finned fish)

Tiktaalik

Temporal range: Tardily Devonian (Frasnian), 375 Ma

PreꞒ

Ꞓ

O

Southward

D

C

P

T

J

K

Pg

N

↓

Possible record in the Middle Devonian

Tiktaalik Chicago.JPG
Tiktaalik in the Field Museum, Chicago
Scientific nomenclature e
Kingdom: Animalia
Phylum: Chordata
Clade: Stegocephalia
Genus: † Tiktaalik
Daeschler, Shubin & Jenkins, 2006
Type species
† Tiktaalik roseae

Daeschler, Shubin & Jenkins, 2006

Tiktaalik (; Inuktitut ᑎᒃᑖᓕᒃ [tiktaːlik]) is a monospecific genus of extinct sarcopterygian (lobe-finned fish) from the Belatedly Devonian Period, about 375 Mya (million years ago), having many features akin to those of tetrapods (four-legged animals).[ane]

Unearthed in Chill Canada, Tiktaalik is a not-tetrapod osteoichthyes, complete with scales and gills – but it has a triangular, flattened head and unusual, cleaver-shaped fins. Its fins accept thin ray bones for paddling like most fish, but they also have sturdy interior bones that would accept allowed Tiktaalik to prop itself up in shallow water and use its limbs for support every bit most four-legged animals do. Those fins and a suite of other characteristics set Tiktaalik apart as something special; it has a combination of features that testify the evolutionary transition between swimming fish and their descendants, the four-legged vertebrates – a clade which includes amphibians, reptiles, birds and mammals.[2]

This beast and similar animals may possibly exist the mutual ancestors of the wide swath of all vertebrate terrestrial brute: amphibians, reptiles, birds, and mammals.[3]

The first well-preserved Tiktaalik fossils were found in 2004 on Ellesmere Island in Nunavut, Canada. The discovery, fabricated by Edward B. Daeschler of the Academy of Natural Sciences, Neil H. Shubin from the University of Chicago, and Harvard Academy Professor Farish A. Jenkins Jr, was published in the Apr half dozen, 2006, effect of Nature [1] and rapidly recognized as a transitional form.

Description [edit]

Tiktaalik provides insights on the features of the extinct closest relatives of the tetrapods. Different many previous, more fishlike transitional fossils, the "fins" of Tiktaalik have basic wrist bones and simple rays reminiscent of fingers. The homology of distal elements is uncertain; there have been suggestions that they are homologous to digits, although this is incompatible with the digital arch developmental model because digits are supposed to be postaxial structures, and merely 3 of the (reconstructed) eight rays of Tiktaalik are postaxial.[4]

However, the proximal series tin exist directly compared to the ulnare and intermedium of tetrapods. The fin was clearly weight begetting, being attached to a massive shoulder with expanded scapular and coracoid elements and fastened to the body armor, big muscular scars on the ventral surface of the humerus, and highly mobile distal joints. The bones of the forefins show big muscle facets, suggesting that the fin was both muscular and had the ability to flex like a wrist joint. These wrist-like features would accept helped ballast the creature to the bottom in fast moving current.[5] [six]

Skull showing spiracle holes to a higher place the eyes

The alligator gar is an extant fish that bears some resemblance to Tiktaalik

Also notable are the spiracles on the top of the caput, which advise the beast had primitive lungs besides as gills. This attribute would take been useful in shallow water, where higher water temperature would lower oxygen content. This development may take led to the development of a more than robust ribcage, a central evolutionary trait of country-living creatures.[7] The more than robust ribcage of Tiktaalik would have helped back up the animal's trunk any time it ventured outside a fully aquatic habitat. Tiktaalik also lacked a characteristic that most fishes have—bony plates in the gill area that restrict lateral head motion. This makes Tiktaalik the earliest known fish to have a neck, with the pectoral girdle separate from the skull. This would give the creature more freedom in hunting prey either on land or in the shallows.[half dozen]

Tiktaalik is sometimes compared to gars (esp. Atractosteus spatula, the alligator gar) of the family unit Lepisosteidae, with whom it shares a number of characteristics:[eight]

  • diamond-shaped scale patterns common to the Crossopterygii class (in both species scales are rhombic, overlapping and tuberculated);
  • teeth structured in two rows;
  • both internal and external nostrils;
  • tubular and streamlined body;
  • absence of inductive dorsal fin;
  • broad, dorsoventrally compressed skull;
  • paired frontal basic;
  • marginal nares;
  • subterminal oral cavity;
  • lung-like organ.

Paleobiology [edit]

Tiktaalik generally had the characteristics of a lobe-finned fish, but with front fins featuring arm-like skeletal structures more alike to those of a crocodile, including a shoulder, elbow, and wrist. The fossil discovered in 2004 did non include the rear fins and tail. It had rows[9] of sharp teeth indicative of a predator fish, and its neck could move independently of its body, which is non mutual in other fish (Tarrasius, Mandageria, placoderms,[10] [xi] and extant seahorses being some exceptions; see also Lepidogalaxias and Channallabes apus [12]). The animal had a flat skull resembling a crocodile's; optics on height of its head; a neck and ribs similar to those of tetrapods, with the ribs existence used to support its body and aid in breathing via lungs; well developed jaws suitable for communicable prey; and a small gill slit called a spiracle that, in more than derived animals, became an ear.[xiii]

The fossils were found in the "Fram Germination", deposits of meandering stream systems nearly the Devonian equator, suggesting a benthic animal that lived on the bottom of shallow waters and perhaps even out of the water for short periods, with a skeleton indicating that it could support its trunk under the force of gravity whether in very shallow water or on land.[xiv] At that period, for the first fourth dimension, deciduous plants were flourishing and annually shedding leaves into the water, attracting small prey into warm oxygen-poor shallows that were difficult for larger fish to swim in.[7] The discoverers said that in all likelihood, Tiktaalik flexed its proto-limbs primarily on the floor of streams and may accept pulled itself onto the shore for brief periods.[fifteen] In 2014, the discovery of the beast's pelvic girdle was announced; it was strongly congenital, indicating the animal could have used them for moving in shallow h2o and across mudflats.[16] Neil Shubin and Daeschler, the leaders of the team, have been searching Ellesmere Isle for fossils since 2000[5] [17]

Tiktaalik'southward discoverers believe the beast ventured onto land but as present day mudskippers do, propping up on their fins

Nosotros're making the hypothesis that this creature was specialized for living in shallow stream systems, maybe swampy habitats, perhaps even to some of the ponds. And mayhap occasionally, using its very specialized fins, for moving up overland. And that's what is particularly of import here. The animal is developing features which will eventually allow animals to exploit land.[18]

Classification and evolution [edit]

Tiktaalik roseae is the only species classified under the genus. Tiktaalik lived approximately 375 million years agone. It is representative of the transition between not-tetrapod vertebrates (fish) such as Panderichthys, known from fossils 380 million years old, and early tetrapods such as Acanthostega and Ichthyostega, known from fossils virtually 365 million years one-time. Its mixture of archaic fish and derived tetrapod characteristics led i of its discoverers, Neil Shubin, to characterize Tiktaalik as a "fishapod".[5] [xix]

Tiktaalik is a transitional fossil; it is to tetrapods what Archaeopteryx is to birds, troodonts and dromaeosaurids. While it may be that neither is ancestor to any living beast, they serve as evidence that intermediates betwixt very dissimilar types of vertebrates did in one case exist. The mixture of both fish and tetrapod characteristics found in Tiktaalik include these traits:

  • Fish
    • fish gills
    • fish scales
    • fish fins
  • "Fishapod"
    • one-half-fish, half-tetrapod limb bones and joints, including a functional wrist joint and radiating, fish-similar fins instead of toes
    • half-fish, one-half-tetrapod ear region
  • Tetrapod
    • tetrapod rib basic
    • tetrapod mobile neck with carve up pectoral girdle
    • tetrapod lungs

Phylogenetic position [edit]

2006 – 2010 [edit]

The phylogenetic assay by Daeschler et al. placed Tiktaalik every bit a sis taxon to Elpistostege and direct above Panderichthys preceded by Eusthenopteron. Tiktaalik was thus inserted below Acanthostega and Ichthyostega equally a transitional form[20] and a true "missing link".[21]

Such order of the phylogenetic tree was initially adopted by other experts, nigh notably by Per Ahlberg and Jennifer Clack.[22] However, it was questioned in a 2008 newspaper by Boisvert et al., who noted that Panderichthys, due to its more derived distal portion, might be closer to tetrapods than Tiktaalik or even that it was convergent with tetrapods.[23] Ahlberg, co-author of the study, considered the possibility of Tiktaalik'southward fin having been "an evolutionary return to a more archaic form."[24]

2010 – now [edit]

In Jan 2010, a group of paleontologists including Ahlberg published a newspaper[25] accompanied by extensive supplementary material[26] (discussed also in a Nature documentary[27] [28]) which showed that the first tetrapods appeared long before Tiktaalik and other elpistostegids. Their conclusions were based on numerous trackways (esp. Muz. PGI 1728.Two.16) and individual footprints (esp. Muz. PGI 1728.Ii.one) discovered at the Zachełmie quarry in the Holy Cross Mountains (Poland). A tetrapod origin of those tracks was suggested based on:

  • distinct digits and limb morphology;
  • trackways reflecting quadrupedal gait and diagonal walk;
  • no body or tail drag marks;
  • very wide footstep in relation to body length (much beyond that of Tiktaalik or any other fish);
  • various size footprints with some unusually big (up to 26 cm wide) indicating trunk lengths of over ii.5 m.

Track-bearing layers were assigned to the lower-eye Eifelian based on conodont index fossil samples (costatus Zone) and "previous biostratigraphic data obtained from the underlying and overlying strata"[25] with subsequent studies confirming this dating.[29] [30] [31]

Zachełmie trackmakers predate non merely ichthyostegids and elpistostegids (including Tiktaalik) but likewise a number of tetrapodomorph fish which until 2010 were unanimously considered ancestors of tetrapods.

Both Tiktaalik's discoverers were skeptical about the Zachelmie trackways. Daeschler said that trace evidence was not plenty for him to modify the theory of tetrapod evolution,[32] while Shubin argued that Tiktaalik could have produced very similar footprints[33] (in a later written report Shubin expressed a significantly modified opinion that some of the Zachelmie footprints, those which lacked digits, may have been made by walking fish[34]). However, Ahlberg insisted that those tracks could not accept possibly been formed either past natural processes or by transitional species such as Tiktaalik or Panderichthys.[25] [35] Instead, the authors of the publication suggested ichthyostegalians equally trackmakers, based on available pes morphology of those animals.[25] Still, a newspaper published in 2015 that undertook a disquisitional review of Devonian tetrapod footprints called into question the designation of the Zachelmie marks and instead suggested an origin as fish nests/feeding traces.[36] An earlier study in 2012 indicated that Zachelmie trackmakers were fifty-fifty more advanced than Ichthyostega in terms of quadrupedalism.[37] Grzegorz Niedźwiedzki's reconstruction of one of the trackmakers was identical to that of Tulerpeton.[38] [39]

Narkiewicz, co-writer of the article on the Zachelmie trackways, claimed that the Shine "discovery has disproved the theory that elpistostegids were the ancestors of tetrapods",[twoscore] a notion partially shared by Philippe Janvier.[41] There have been a number of new hypotheses suggested as to a possible origin and phylogenetic position of the elpistostegids (including Tiktaalik):

  • their phylogenetic position remains unchanged and the footprints plant in the Holy Cantankerous Mountains are attributed to tetrapods merely as a upshot there are at least half-dozen long ghost lineages separating Zachelmie trackmakers from various elpistostegalian and ichthyostegalian species;[25]
  • they were "late-surviving relics rather than direct transitional forms";[38] [42]
  • they were "an evolutionary expressionless-end";[43]
  • they were a result of convergent or parallel evolution so that apomorphies and hit anatomical similarities plant in both digited tetrapods and elpistostegalians evolved at least twice.[44] [45] [46]

Convergency is considered responsible for uniquely tetrapod features found likewise in other non-elpistostegalian fish from the period like Sauripterus (finger-like jointed distal radial bones)[47] [48] or Tarrasius (tetrapod-like spine with 5 axial regions).[49]

Estimates published subsequently the discovery of Zachelmie tracks suggested that digited tetrapods may have appeared as early as 427.4 Ma agone and questioned attempts to read accented timing of evolutionary events in early tetrapod development from stratigraphy.[45]

Until more data become available, the phylogenetic position of Tiktaalik and other elpistostegids remains uncertain.

Discovery [edit]

Discovery site of Tiktaalik fossils

In 2004, 3 fossilized Tiktaalik skeletons were discovered in the Tardily Devonian fluvial Fram Formation on Ellesmere Isle, Nunavut, in northern Canada.[50] [51] Estimated ages reported at 375 MYA, 379 MYA, and 383 MYA. At the fourth dimension of the species' being, Ellesmere Isle was part of the continent Laurentia (modern eastern North America and Greenland),[52] which was centered on the equator and had a warm climate. When discovered, one of the skulls was found sticking out of a cliff. Upon farther inspection, the fossil was found to be in excellent status for a 375-meg-year-old specimen.[5] [17]

The discovery past Daeschler, Shubin, and Jenkins was published in the April 6, 2006, issue of Nature [1] and quickly recognized as a transitional course. Jennifer A. Clack, a Cambridge University expert on tetrapod evolution, said of Tiktaalik, "It's one of those things you tin point to and say, 'I told you lot this would exist,' and in that location it is."[half-dozen]

Neil Shubin, 1 of the paleontologists who discovered Tiktaalik, belongings a cast of its skull

Later five years of digging on Ellesmere Island, in the far north of Nunavut, they hit pay clay: a collection of several fish so beautifully preserved that their skeletons were still intact. As Shubin'due south team studied the species they saw to their excitement that it was exactly the missing intermediate they were looking for. 'We institute something that really split the difference correct downward the middle,' says Daeschler.

— [53]

The name Tiktaalik is an Inuktitut word meaning "large freshwater fish".[3] The "fishapod" genus received this proper name after a proffer past Inuit elders of Canada's Nunavut Territory, where the fossil was discovered.[52] The specific name roseae cryptically honours an bearding donor.[54] Taking a detailed look at the internal head skeleton of Tiktaalik roseae, in the Oct 16, 2008, issue of Nature,[55] researchers show how Tiktaalik was gaining structures that could let it to support itself on solid ground and breathe air, a key intermediate step in the transformation of the skull that accompanied the shift to life on state past our distant ancestors.[56]

Cultural significance [edit]

Internet users have contradistinct an illustration of Tiktaalik by artist Zina Deretsky to create memes.[57] The images mostly humorously criticize Tiktaalik for its evolutionary adaptations, construing them as playing a critical part in the chain of events that would eventually lead to all man suffering.[57]

Run across also [edit]

  • Walking fish
  • Alligator gar
  • Amphibious fish
  • Spotted handfish

Other lobe-finned fish found in fossils from the Devonian Period:

  • Coelacanth
  • Eusthenopteron
  • Gogonasus
  • Ichthyostega
  • Panderichthys

References [edit]

  1. ^ a b c Edward B. Daeschler, Neil H. Shubin and Farish A. Jenkins Jr. (six Apr 2006). "A Devonian tetrapod-similar fish and the evolution of the tetrapod body plan". Nature. 440 (7085): 757–763. Bibcode:2006Natur.440..757D. doi:10.1038/nature04639. PMID 16598249.
  2. ^ "What has the head of a crocodile and the gills of a fish?". development.berkeley.edu. Archived from the original on 2018-06-12. Retrieved 2018-06-06 .
  3. ^ a b Shubin, Neil (2008). Your Inner Fish: A Journey into the 3.5-Billion-Yr History of the Human Body. New York: University of Chicago Press. ISBN9780375424472.
  4. ^ Laurin M (2006). "Scanty evidence and irresolute opinions about evolving appendages". Zoologica Scripta. 35 (vi): 667–668. doi:10.1111/zsc.2006.35.issue-6.
  5. ^ a b c d Shubin, Neil (2008). Your Inner Fish. Pantheon. ISBN978-0-375-42447-2.
  6. ^ a b c Holmes, Bob (2007). "Encounter Your antecedent, the Fish that crawled". New Scientist. Archived from the original on 2016-04-xiii. Retrieved 2007-02-07 .
  7. ^ a b Jennifer A. Clack, Scientific American, Getting a Leg Up on Land Archived 2013-12-07 at the Wayback Motorcar November 21, 2005.
  8. ^ Spitzer, Mark (2010). Season of the Gar: Adventures in Pursuit of America'southward Almost Misunderstood Fish. Academy of Arkansas Press. pp. 65–66. ISBN978-ane-55728-929-ii. Archived from the original on 2014-01-07. Retrieved 2016-10-29 .
  9. ^ "Fossil Suggests Missing Link From Fish to Land". NPR (National Public Radio). Archived from the original on 2006-10-13. Retrieved 2006-11-27 .
  10. ^ One thousand. Trinajstic et al. (12 July 2013). "Fossil Musculature of the Well-nigh Primitive Jawed Vertebrates". Scientific discipline. 341 (6142): 160–164. Bibcode:2013Sci...341..160T. doi:ten.1126/science.1237275. PMID 23765280. S2CID 39468073. {{cite journal}}: CS1 maint: uses authors parameter (link)
  11. ^ "Primitive fish could nod just not milkshake its head: Ancient fossils reveal surprises virtually early vertebrate necks, abdominal muscles". Science News. June 13, 2013. Archived from the original on December 15, 2013. Retrieved December xiv, 2013.
  12. ^ Sam Van Wassenbergh; Anthony Herrel; Dominique Adriaens; Frank Huysentruyt; Stijn Devaere & Peter Aerts (13 April 2006). "Evolution: A catfish that can strike its prey on state". Nature. 440 (7086): 881. Bibcode:2006Natur.440..881V. doi:ten.1038/440881a. PMID 16612372. S2CID 4423295.
  13. ^ Dalton, Rex (2006). "The fish that crawled out of the water". Nature: news060403–7. doi:ten.1038/news060403-7. S2CID 129031187. Archived from the original on 2006-04-11. Retrieved 2006-04-06 .
  14. ^ The Academy of Natural Sciences, Philadelphia, printing release Apr 3, 2006. (doc)
  15. ^ Neil H. Shubin, Edward B. Daeschler and Farish A. Jenkins Jr (6 April 2006). "The pectoral fin of Tiktaalik roseae and the origin of the tetrapod limb". Nature. 440 (7085): 764–771. Bibcode:2006Natur.440..764S. doi:10.1038/nature04637. PMID 16598250. S2CID 4412895.
  16. ^ Shubin, N. H.; Daeschler, E. B.; Jenkins, F. A. (2014). "Pelvic girdle and fin of Tiktaalik roseae". Proceedings of the National University of Sciences. 111 (3): 893–899. Bibcode:2014PNAS..111..893S. doi:x.1073/pnas.1322559111. PMC3903263. PMID 24449831.
  17. ^ a b Peterson, Britt (April five, 2006). "An Evolutionary Finding". Seed. Archived from the original on April xi, 2006. Retrieved April 5, 2006. {{cite news}}: CS1 maint: unfit URL (link)
  18. ^ NewsHour, Fossil Discovery Archived 2014-01-22 at the Wayback Car, April 6, 2006.
  19. ^ John Noble Wilford, The New York Times, Scientists Call Fish Fossil the Missing Link Archived 2017-xi-15 at the Wayback Automobile, Apr. 5, 2006.
  20. ^ Daeschler, Edward B.; Shubin, Neil H.; Jenkins, Farish A. Jr (6 April 2006). "A Devonian tetrapod-like fish and the evolution of the tetrapod torso plan" (PDF). Nature. 440 (7085): 757–763. Bibcode:2006Natur.440..757D. doi:10.1038/nature04639. PMID 16598249. S2CID 4413217. Archived (PDF) from the original on 12 Feb 2015. Retrieved 24 January 2015.
  21. ^ Rex Dalton (v Apr 2006). "The fish that crawled out of the water". Nature. doi:ten.1038/news060403-7. Archived from the original on 24 January 2015. Retrieved 24 Jan 2015.
  22. ^ Ahlberg, Per Erik; Clack, Jennifer A. (6 Apr 2006). "A firm step from h2o to land". Nature. 440 (7085): 747–749. Bibcode:2006Natur.440..747A. doi:ten.1038/440747a. PMID 16598240. S2CID 4392361.
  23. ^ Boisvert, Catherine A.; Marker-Kurik, Elga; Ahlberg, Per E. (4 Dec 2008). "The pectoral fin of Panderichthys and the origin of digits". Nature. 456 (7222): 636–638. Bibcode:2008Natur.456..636B. doi:x.1038/nature07339. PMID 18806778. S2CID 2588617. Archived from the original on 4 January 2014. Retrieved 24 Jan 2015. Given that recent phylogenies consistently place Panderichthys below Tiktaalik in the tetrapod stem grouping, it is surprising to notice that its pectoral fin skeleton is more than limb-like than that of its supposedly more derived relative. [...] Information technology is difficult to say whether this character distribution implies that Tiktaalik is autapomorphic, that Panderichthys and tetrapods are convergent, or that Panderichthys is closer to tetrapods than Tiktaalik.
  24. ^ Ker Than (September 24, 2008). "Ancient Fish Had Primitive Fingers, Toes". National Geographic News. National Geographic Gild. Archived from the original on September 27, 2008. Curiously, the radial bones of Panderichthys are more finger-like than those of Tiktaalik, a fish with chubby leg-similar limbs that lived about five 1000000 years later. Many scientists regard Tiktaalik as a "missing link": the crucial transitional fauna between fish and the first tetrapods. I possibility, Ahlberg said, is that finger evolution took a step astern with Tiktaalik, and that Tiktaalik'southward fins represented an evolutionary return to a more archaic form.
  25. ^ a b c d e Niedźwiedzki, Grzegorz; Szrek, Piotr; Narkiewicz, Katarzyna; Narkiewicz, Marek; Ahlberg, Per E. (vii January 2010). "Tetrapod trackways from the early Center Devonian Catamenia of Poland". Nature. 463 (7277): 43–48. Bibcode:2010Natur.463...43N. doi:10.1038/nature08623. PMID 20054388. S2CID 4428903.
  26. ^ Niedźwiedzki, Grzegorz; Szrek, Piotr; Narkiewicz, Katarzyna; Narkiewicz, Marek; Ahlberg, Per E. (2010). "Tetrapod trackways from the early Middle Devonian Menstruation of Poland. Supplementary data". Nature. 463 (7277): 43–8. Bibcode:2010Natur.463...43N. doi:10.1038/nature08623. PMID 20054388. S2CID 4428903.
  27. ^ Walking with tetrapods. Nature. January vi, 2010. Archived from the original (FLV) on December 20, 2014.
  28. ^ Jonathan Amos (6 January 2010). "Fossil tracks record 'oldest state-walkers'". BBC. Archived from the original on January 7, 2010.
  29. ^ Narkiewicz, Katarzyna; Narkiewicz, Marek (one March 2010). "Mid Devonian carbonate platform evolution in the Holy Cantankerous Mts. area (cardinal Poland): new constraints from the conodont Bipennatus creature". Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen. 255 (3): 287–300. doi:ten.1127/0077-7749/2009/0025.
  30. ^ Niedźwiedzki, Grzegorz; Narkiewicz, Marek; Szrek, Piotr (2014). "The age of the oldest tetrapod tracks from Zachełmie, Poland". Bulletin of Geosciences. 89 (3): 593–606. Archived from the original on 2015-05-11. Retrieved 2015-01-24 .
  31. ^ Narkiewicz, Katarzyna; Narkiewicz, Marek (January 2015). "Middle Devonian invertebrate trace fossils from the marginal marine carbonates of the Zachełmie tetrapod tracksite, Holy Cantankerous Mountains, Poland". Lethaia. 48 (1): 10–12. doi:10.1111/let.12083.
  32. ^ "Trace evidence is not enough for me to change my listen about accepted theories on tetrapod evolution" – Daeschler as quoted in Rex Dalton (January 6, 2010). "Discovery pushes back date of first 4-legged animal". Nature: news.2010.1. doi:x.1038/news.2010.1. Archived from the original on March 8, 2014. "I am non ready to discard the established paradigm for the fish-tetrapod transition" – Daeschler as quoted in Jef Akst (January 6, 2010). "Tetrapods' sometime historic period revealed". The Scientist. Archived from the original on March iv, 2016. Retrieved Nov 10, 2019. "With all respect to the scientists involved in this study, at that place may be other explanations for these suggestive tracks." – Daeschler as quoted in Dan Vergano (January 6, 2010). "Four-legged finding muddies paleontological waters". USA Today. Archived from the original on December 24, 2014.
  33. ^ [Neil Shubin] says that a model of Tiktaalik'due south skeleton would produce a print much like the ane in the paper if it's mushed into sand, and dissimilar consistencies or angles would produce an even closer friction match. He adds, "There is nothing in Tiktaalik'south described anatomy that suggests it didn't accept a footstep." in Ed Yong (January 6, 2010). "Fossil tracks button dorsum the invasion of country past 18 million years". Observe. Archived from the original on May 16, 2010.
  34. ^ King, Heather M.; Shubin, Neil H.; Coates, Michael I.; Hale, Melina E. (Dec 27, 2011). "Behavioral bear witness for the evolution of walking and bounding before terrestriality in sarcopterygian fishes". PNAS. 108 (52): 21146–21151. Bibcode:2011PNAS..10821146K. doi:10.1073/pnas.1118669109. PMC3248479. PMID 22160688. It follows that the attribution of some of the nondigited Devonian fossil trackways to limbed tetrapods may need to be revisited.
  35. ^ "You can run into anatomical details consequent with a footprint, including sediments displaced past a human foot coming downwards", "In that location is no mode these could exist formed by a natural process." - Ahlberg every bit quoted in Rex Dalton (January 6, 2010). "Discovery pushes back date of first four-legged animal". Nature: news.2010.ane. doi:10.1038/news.2010.1. Archived from the original on March 8, 2014.
  36. ^ Lucas, Spencer G. (2015). "Thinopus and a Critical Review of Devonian Tetrapod Footprints" (PDF). Ichnos. 22 (3–4): 136–154. doi:10.1080/10420940.2015.1063491. S2CID 130053031.
  37. ^ Pierce, Stephanie E.; Clack, Jennifer A.; Hutchinson, John R. (28 June 2012). "Three-dimensional limb joint mobility in the early tetrapod Ichthyostega" (PDF). Nature. 486 (7404): 523–526. Bibcode:2012Natur.486..523P. doi:10.1038/nature11124. PMID 22722854. S2CID 3127857.
  38. ^ a b Niedźwiedzki, Grzegorz; Szrek, Piotr (2010). "Way to Go!" (PDF). Academia. 2 (26): 28–31. ISSN 1731-7401. OCLC 786293607. Archived from the original (PDF) on January 19, 2015.
  39. ^ The 2007 creative restoration of Tulerpeton by Dmitry Bogdanov bachelor at Wikimedia is near identical to the 2008 rendering of a Zachelmie trackmaker past Grzegorz Niedźwiedzki.
  40. ^ Westward.Ż. (February 4, 2010). "A Creature That Time Forgot". The Warsaw Voice. Warsaw. Archived from the original on Dec 22, 2014. ; "W Polsce odkryto ślady najstarszych kopalnych czworonogów" [Oldest tetrapod fossil footprints discovered in Poland]. Scientific discipline & Scholarship in Poland (Polish Press Agency) (in Shine). Warsaw. January 7, 2010. Archived from the original on December 22, 2014.
  41. ^ "We now take to invent a mutual antecedent to the tetrapods and elpistostegids." – Janvier as quoted in Karen McVeigh (January half-dozen, 2010). "Footprints show tetrapods walked on land 18m years earlier than thought". The Guardian. London. Archived from the original on March 2, 2014.
  42. ^ Editor'south summary (7 January 2010). "4 feet in the by: trackways pre-date earliest torso fossils". Nature. 463 (7277): xl–ane. Bibcode:2010Natur.463...40J. doi:ten.1038/463040a. PMID 20054387. S2CID 447958. Archived from the original on Nov 3, 2012. {{cite journal}}: CS1 maint: uses authors parameter (link)
  43. ^ "Ancient Iv-Legged Beasts Leave Their Marker". Science. half dozen January 2010. Archived from the original on September 30, 2013.
  44. ^ Janvier, Philippe; Clément, Gaël (seven January 2010). "Muddy tetrapod origins". Nature. 463 (7277): 40–41. Bibcode:2010Natur.463...40J. doi:10.1038/463040a. PMID 20054387. S2CID 447958.
  45. ^ a b Friedman, Matt; Brazeau, Martin D. (vii Feb 2011). "Sequences, stratigraphy and scenarios: what tin we say nearly the fossil record of the earliest tetrapods?". Proceedings of the Regal Lodge B. 278 (1704): 432–439. doi:10.1098/rspb.2010.1321. PMC3013411. PMID 20739322.
  46. ^ Gee, Henry (January vi, 2010). "Offset Ground". SciLogs. Archived from the original on December 22, 2014. It is possible that the close similarity betwixt elpistostegids and tetrapods might accept been the event of evolutionary convergence. The common ancestor of elpistostegids and tetrapods wouldn't have to have looked similar Tiktaalik – it could have been a more undifferentiated, tetrapodomorph fish. Elpistostegids and tetrapodomorphs, each following their own paths, grew to look more and more like one other.
  47. ^ Daeschler, Edward B.; Shubin, Neil (eight January 1998). "Fish with fingers?". Nature. 391 (6663): 133. Bibcode:1998Natur.391..133D. doi:x.1038/34317. S2CID 4386457.
  48. ^ Davis, Marcus C.; Shubin, Neil; Daeschler, Edward B. (2004). "A new specimen of Sauripterus taylori (Sarcopterygii, Osteichthyes) from the Famennian Catskill Germination of Northward America". Journal of Vertebrate Paleontology. 24 (1): 26–40. doi:ten.1671/1920-iii. S2CID 128815066.
  49. ^ Sallan, Lauren Cole (22 Baronial 2012). "Tetrapod-like axial regionalization in an early ray-finned fish". Proceedings of the Royal Society B. 279 (1741): 3264–3271. doi:10.1098/rspb.2012.0784. PMC3385743. PMID 22628471.
  50. ^ Gorner, Peter (2006-04-05). "Fossil could exist fish-to-land link". Chicago Tribune.
  51. ^ Easton, John (2008-10-23). "Tiktaalik's internal beefcake explains evolutionary shift from h2o to country". University of Chicago Chronicle. Academy of Chicago. 28 (iii). Archived from the original on 2012-04-07. Retrieved 2009-07-nineteen .
  52. ^ a b Spotts, Peter (Apr 6, 2006). "Fossil fills gap in move from sea to land". The Christian Science Monitor. Archived from the original on April half-dozen, 2006. Retrieved 2006-04-05 .
  53. ^ Holmes, Bob (5 April 2006). "Showtime fossil of fish that crawled onto land discovered". New Scientist News. Archived from the original on 6 April 2006. Retrieved 2006-04-07 .
  54. ^ Coyne, Jerry (2009). Why Evolution is True. Viking. ISBN978-0-670-02053-9. Archived from the original on 2019-10-07. Retrieved 2019-09-03 .
  55. ^ Jason P. Downs, Edward B. Daeschler, Farish A. Jenkins & Neil H. Shubin (16 Oct 2008). "The cranial endoskeleton of Tiktaalik roseae". Nature. 455 (7215): 925–929. Bibcode:2008Natur.455..925D. doi:ten.1038/nature07189. PMID 18923515. S2CID 4411801. {{cite journal}}: CS1 maint: multiple names: authors listing (link)
  56. ^ "Fishapod" Reveals Origins of Head and Neck Structures of Starting time Land Animals Archived 2008-10-19 at the Wayback Machine Newswise, Retrieved on October 15, 2008.
  57. ^ a b Imbler, Sabrina (29 April 2022). "Started Out as a Fish. How Did It Cease Up Like This?". The New York Times . Retrieved 29 Apr 2022.

External links [edit]

  • University of Chicago website dedicated to the discovery
  • Interview with Neil Shubin on The Inoculated Heed, Feb 12, 2008.
  • Interview with Neil Shubin on Tech Nation where he discusses the discovery of the Tiktaalik, February 14, 2008.
  • Lecture (presentation) by Neil Shubin about the discovery of Tiktaalik on YouTube
  • Fishapod stars in music video, YouTube. Accessed on December 27, 2008.
  • Finding Tiktaalik: Interview with Neil Shubin, Royal Institution video, February 2013
  • A today's fish with tetrapod beefcake, able to movement like an early tetrapod – Cryptotora thamicola

Source: https://en.wikipedia.org/wiki/Tiktaalik

Posted by: schubertmompok.blogspot.com

0 Response to "What Was The First Animal To Walk On Land"

Post a Comment

Subscribe to: Post Comments (Atom)

Iklan Atas Artikel

Iklan Tengah Artikel 1

Iklan Tengah Artikel 2

Iklan Bawah Artikel