Lafonius
| Lafonius Temporal range: Carboniferous, | |
|---|---|
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Clade: | Tetrapoda |
| Order: | †Temnospondyli |
| Suborder: | †Dvinosauria |
| Family: | †Trimerorhachidae |
| Genus: | †Lafonius Berman, 1973 |
| Type species | |
| †Lafonius lehmani Berman, 1973 | |
Lafonius is an extinct genus dvinosaurian temnospondyl within the family Trimerorhachidae. It is known from the late Carboniferous of New Mexico.[1] It is represented only by the type species, Lafonius lehmani.
History of study
[edit]The holotype and only known specimen of Lafonius lehmani was discovered in 1971 by Neal La Fon and Thomas Lehman, amateur fossil collectors in New Mexico, who collected the specimen from a rich fossil-bearing locality in the Manzano Mountains of New Mexico that is now known as the Kinney Brick Quarry (Tinajas Member of the Astrasado Formation).[1][2][3][4] The genus and species epithets honor these collectors.
Anatomy
[edit]The holotype is a partial, disarticulated skeleton on a slab, with a nearly complete skull (mainly the roof) and pair of lower jaws and more fragmentary limb, vertebral, scale, and branchial elements. The skull is relatively small, being around 2 cm when complete, and relatively short anteroposteriorly compared to other taxa (which are often known from larger specimens). Based on this and aspects of the branchial apparatus, it has been interpreted as a larval individual.[5][6] Berman (1973) diagnosed the taxon as a Trimerorhachis-like trimerorhachid that differs from Trimerorhachis in having a broad jugal-orbit contact; a double row of coronoid teeth restricted to the second (middle) coronoid with a pair of tusks (enlarged teeth) on the first (anterior) and last (posterior) coronoids; lesser elongation of the postorbital region, which is mainly formed by elongation of elements posterior to the pineal foramen rather than more anterior elements; and a deeper otic notch.[1] Schoch & Milner (2014) reduced the diagnosis to only two features, the broad jugal-orbit contact and the dentition pattern of the coronoids.[5] It is differentiated from the co-occurring dvinosaur Bermanerpeton kinneyi (the "indeterminate saurerpetontid" of Hunt et al., 1992)[2] by features including (1) small orbits; (2) elongated and wide postorbital region; (3) nasal as wide as long; (4) intertemporal present; (5) postorbital elongated; (6) postparietal much more elongated than tabular; and (7) short and robust humerus and femur.[7]
Phylogenetic relationships
[edit]Lafonius was originally classified as a trimerorhachid by Berman (1973) and has been maintained as such by other workers.[1][8][5] Given the larval status of the holotype and the relative incompleteness compared to other trimerorhachids, Lafonius is not usually incorporated into phylogenetic analyses of dvinosaurs.[9][10]
References
[edit]- 1 2 3 4 Berman, David S. (1973). "A Trimerorhachid Amphibian from the Upper Pennsylvanian of New Mexico". Journal of Paleontology. 47 (5). Paleontological Society: 932–945. ISSN 0022-3360. JSTOR 1303077.
- 1 2 Hunt, Adrian P.; Lucas, Spencer G.; Berman, David S (1992). "The Late Pennsylvanian amphibian fauna of the Kinney Quarry, central New Mexico". New Mexico Bureau of Mines & Mineral Resources Bulletin. 138: 211–220.
- ↑ Williams, Sally; Lucas, Spencer G. (2013). "Taphonomy and paleoecology of Pennsylvanian fishes from the Kinney Brick Quarry, New Mexico, USA". New Mexico Museum of Natural History and Science Bulletin. 60: 371–389.
- ↑ Schneider, Joerg W.; Legler, Berit; Brosig, Andreas; Krainer, Karl; Lucas, Spencer G. (2021). "Sedimentology and depositional environment of the Kinney Brick Quarry Fossil Lagerstätte (Missourian, Late Pennsylvanian), central New Mexico". New Mexico Museum of Natural History and Science Bulletin. 84: 93–123.
- 1 2 3 Schoch, Rainer R.; Milner, Andrew R. (2014), Wellnhofer, Peter; Sues, Hans-Dieter (eds.), Handbuch der Paläoherpetologie Part 3A2: Temnospondyli I, München: Verlag Dr. Friedrich Pfeil, ISBN 978-3-89937-170-3
- ↑ Schoch, Rainer R.; Witzmann, Florian (October 2024). "The evolution of larvae in temnospondyls and the stepwise origin of amphibian metamorphosis". Biological Reviews. 99 (5): 1613–1637. doi:10.1111/brv.13084. ISSN 1464-7931. PMID 38599802.
- ↑ Werneburg, Ralf R.; Schneider, Joerg W.; Lucas, Spencer G. (2021). "The new dvinosaurian Bermanerpeton kinneyi (Temnospondyli), with "branchiosaurid" characters, from the late Pennsylvanian Kinney brick quarry in New Mexico". New Mexico Museum of Natural History and Science Bulletin. 84: 433–451.
- ↑ Milner, Andrew R.; Schoch, Rainer R. (2013-10-01). "Trimerorhachis (Amphibia: Temnospondyli) from the Lower Permian of Texas and New Mexico: cranial osteology, taxonomy and biostratigraphy". Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen. 270 (1): 91–128. Bibcode:2013NJGPA.270...91M. doi:10.1127/0077-7749/2013/0360. ISSN 0077-7749.
- ↑ Schoch, Rainer R.; Voigt, Sebastian (2019-01-02). "A dvinosaurian temnospondyl from the Carboniferous-Permian boundary of Germany sheds light on dvinosaurian phylogeny and distribution". Journal of Vertebrate Paleontology. 39 (1) e1577874. Bibcode:2019JVPal..39E7874S. doi:10.1080/02724634.2019.1577874. ISSN 0272-4634.
- ↑ Marsicano, Claudia; Angielczyk, Kenneth D.; Cisneros, Juan C.; Richter, Martha; Kammerer, Christian F.; Fröbisch, Jörg; Smith, Roger M. H. (2021-01-02). "Brazilian Permian dvinosaurs (Amphibia, Temnospondyli): revised description and phylogeny". Journal of Vertebrate Paleontology. 41 (1) e1893181. Bibcode:2021JVPal..41E3181M. doi:10.1080/02724634.2021.1893181. ISSN 0272-4634.
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