identifier	taxonID	type	CVterm	format	language	title	description	additionalInformationURL	UsageTerms	rights	Owner	contributor	creator	bibliographicCitation
3368537B6035FFF4FF77F9AD6FA6F91B.text	3368537B6035FFF4FF77F9AD6FA6F91B.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Diploctenium Goldfuss 1826	<div><p>Genus?  Diploctenium Goldfuss, 1826</p><p>Type Species.  Diploctenium cordatum Goldfuss, 1826</p></div>	https://treatment.plazi.org/id/3368537B6035FFF4FF77F9AD6FA6F91B	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		MagnoliaPress via Plazi	Collado, Gonzalo A.;Galleguillos, Fernando F.	Collado, Gonzalo A., Galleguillos, Fernando F. (2025): A new species of? Diploctenium (Anthozoa: Meandrinidae) from the Trihueco Formation (Lower Paleocene), south-central Chile. Zootaxa 5584 (2): 281-287, DOI: 10.11646/zootaxa.5584.2.8, URL: https://doi.org/10.11646/zootaxa.5584.2.8
3368537B6035FFF1FF77F8E16F60FE1B.text	3368537B6035FFF1FF77F8E16F60FE1B.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Diploctenium chilensis Collado & Galleguillos 2025	<div><p>?  Diploctenium chilensis,  new species</p><p>Figure 2A–D</p><p>Holotype. Specimen almost complete (MGUC PT/01 -L2/C2) (Fig. 2A–D).</p><p>Description of the holotype. Solitary coral, flabelliform, with a thick triangular pedicel. Thecal edge crest extends to about one quarter of the corallum, corresponding to the summit of the pedicel; columella not observed due to preservation. Calice perimeter dentate, characterized by conspicuous costosepta arranged in four alternating size cycles that extend toward the center. There are at least 33 long septa, each with a fang-like appearance. Outer wall with marked and numerous costae that originate from the base of the pedicel and distinctly bifurcate as they extend to the upper margin of the corallum.</p><p>Dimensions of the holotype. Height 2.3 cm (measured as a straight line from the base of the pedicel to the margin of the calice in Figure 2B), width 2.9 cm (measured as a straight line connecting the two wings of the specimen over the pedicel in Figure 2B).</p><p>Type locality.   Millaneco Beach, south of  Lebu, Arauco Province, Bío-Bío Region, south-central Chile (Fig. 1)  .</p><p>Geological horizon.   Trihueco Formation of the  Lower Paleocene in the Arauco Basin along the coast of the Bío-Bío Region, according to the geological setting described by Becerra et al. (2013)  .</p><p>Etymology. The name derives from Chile, where the fossil was found.</p><p>Comparisons with other species. In terms of general morphology,?  Diploctenium chilensis sp. nov. is trianguliform and wider than it is tall, distinguishing it from the type species,  Diploctenium cordatum Goldfuss, 1826, from the Maastrichtian (Upper Cretaceous) of Netherlands, which has a heart shape and is taller than it is wide (Goldfuss 1826; Alloiteau 1952).?  Diploctenium chilensis sp. nov. exhibits a very similar shape when compared to  Diploctenium matheroni Michelin, 1847,  Diploctenium simplex Alloiteau, 1952, and  Diploctenium jacobi Alloiteau, 1952 from the Santonian (Upper Cretaceous) of France, as well as  Diploctenium zuffardii Maccagno, 1942 (Fig. 3), from the Maastrichtian of Libya (Michelin 1847; Alloiteau 1952; Maccagno 1942; Manni 2006; GBIF 2024). However,  Diploctenium simplex differs from the new species by having thicker costae, a shorter pedicel, and poorly developed thecal edge crests, with the lateral margin of the wall between the base of the pedicel and the edge of the calice being nearly straight (Alloiteau 1952). Both  Diploctenium matheroni and  Diploctenium zuffardii are distinguished from the new species by their narrower pedicel and finer costae (Michelin 1847; Alloiteau 1952; Maccagno 1942; Manni 2006).  Diploctenium jacobi is distinguished from?  Diploctenium chilensis sp. nov. by its semicircular shape and thicker, trifurcating costae (Alloiteau 1952).</p><p>?  Diploctenium chilensis sp. nov. differs from  Diploctenium gracile de Fromentel, 1862 (Maastrichtian) and  Diploctenium parvum Alloiteau, 1952, from the Campanian (Upper Cretaceous) of France, which have a conical shape and an acuminate pedicel(de Fromentel 1862; Alloiteau 1952). It also differs from  Diploctenium crassicostatum Alloiteau, 1952 (Campanian), which is much wider than it is tall and has thick costae arranged in pairs (Alloiteau 1952).  Diploctenium cureti Alloiteau, 1952 (Campanian), like  Diploctenium chilensis sp. nov., is also wider than it is tall, but in the former species the thecal edge crests almost reach the summit of the pedicel (Alloiteau 1952).</p><p>?  Diploctenium chilensis sp. nov. differs from  Diploctenium lunatum (Bruguière, 1792),  Diploctenium plumum Goldfuss, 1827,  Diploctenium subcirculare Milne-Edwards &amp; Haime, 1848,  Diploctenium lamellosum d’Orbigny, 1850,  Diploctenium ferrumequinum Reuss, 1854,  Diploctenium pavoninum Reuss, 1854,  Diploctenium affine Felix, 1903,  Diploctenium falloti Bataller, 1936,  Diploctenium arnaudi Alloiteau, 1952,  Diploctenium corbariensis Alloiteau, 1952,  Diploctenium enigma Alloiteau, 1952,  Diploctenium epagnacensis Alloiteau, 1952,  Diploctenium lutaudi Alloiteau, 1952,  Diploctenium mixtum Alloiteau, 1952,  Diploctenium petrocoriensis Alloiteau, 1952,  Diploctenium provincialis Alloiteau, 1952,  Diploctenium toucasi Alloiteau, 1952, and  Diploctenium uxacalcensis Alloiteau, 1952, which have a semicircular or subcircular outline (Alloiteau 1952; Gameil 2005; Baron‐Szabo 2006; GBIF 2024). The new species differs from  Diploctenium pluma Goldfuss, 1826, which has a heart shape, with a more pronounced lobe.</p><p>Remarks. The classification of the genus  Diploctenium at the family group has historically posed challenges. Goldfuss (1826) established the genus to include two species from the Netherlands, but he did not assign it to any family or other suprageneric category. Milne Edwards &amp; Haime (1848) placed the genus informally between the “Eusmiliens” in the family of the “Astréides”. Reuss (1854) placed the genus in the subfamily  Eusmilinae Milne-Edwards &amp; Haime, 1857, family  Astraeidae Dana, 1846, a classification accepted by Milne Edwards (1857). Duncan (1884) recognized this classification at the family level but placed the group in the subfamily “Astraeide simplices”, “alliance” Trochosmilioida. In the 20th century, Felix (1903) classified  Diploctenium in the tribu “Phillosmiliaceae”, subfamily  Trochosmilinae Milne-Edwards, 1857, family “  Turbinolidae ” Milne Edwards &amp; Haime, 1848. Siemiradzki (1925) grouped the genus in the family  Trochosmilidae Milne-Edwards, 1857, while Wells (1956) relocated it to the subfamily  Meandrininae Gray, 1847, family  Meandrinidae Gray, 1847 . Subsequently, Baron-Szabo (1998, 2000) included the group in the family  Dendrogyridae Alloiteau, 1952, but it was soon reclassified back to  Meandrinidae (Baron-Szabo 2006; Baron-Szabo &amp; Leloux 2024). The Paleobiology Database (Uhen et al. 2023) currently assigns the genus to this last family.</p><p>Meandrinidae has been shown to be polyphyletic according to molecular analysis (Fukami et al. 2008). The polyphyletic nature of the family may be attributed to character convergence, a phenomenon frequently observed in corals (Fukami et al. 2004, 2008; Budd &amp; Stolarski 2009), as well as to the poor initial definition of the taxon (Löser et al. 2010). For this reason, different species assigned to this family may occupy distinct clades within the  Scleractinia tree (Fukami et al. 2004, 2008). Consequently,  Diploctenium may need to be assigned to another family. Another candidate is the family  Trochosmilidae de Fromentel, 1861, which includes taxa with a lamellar columella, a pseudocolumella, or without columella (Ogilvie 1896; Yabe &amp; Eguchi 1941). The family  Phyllosmiliidae Felix, 1903 may also be a candidate.</p><p>The presence of a columella in  Diploctenium has historically been controversial. In Goldfuss’s (1826) generic concept, he does not mention the presence of a columella, nor does he refer to it in the two newly described species that accompanied the original description of the genus.According to Milne Edwards (1857), in  Diploctenium “...n’existe pas de columelle,” a character he recognized in other corals but not in the 11  Diploctenium species he treated. Reuss (1854) also did not mention the presence of a columella in the six species he characterized. Similarly, Siemiradzki (1925) and Wells (1956) did not observe a columella in their brief characterizations of the genus. Conversely, Felix (1903), Alloiteau (1952), and Baron-Szabo (1998, 2000, 2006) recognized a well-formed columella in all the species they examined, including some that were addressed by earlier authors where this character was not found.</p><p>Based on the fan-like shape, the pedicel being shorter than the thecal edge crests, and the similarities between the new species and the type species of  Diploctenium (see Fig. 6 in Baron-Szabo 2006, p. 68), as well as other congeners, we assign the new species to this taxon, with the understanding that this classification may be reconsidered if additional material becomes available. It is important to note that  Diploctenium zuffardii, which is very similar to?  Diploctenium chilensis sp. nov. (Fig. 3), was previously considered a potential synonym of  Rennensismilia inflexa (Reuss, 1854) (Baron‐Szabo 2006), a species from Africa, Asia, and Europe. However, we regard the two species as distinct. Further studies, preferably based on material beyond the type specimen, are needed to confirm that?  Diploctenium chilensis sp. nov. belongs to this genus. For this reason, we use the symbol ‘?’ to tentatively classify the new species within  Diploctenium .</p></div>	https://treatment.plazi.org/id/3368537B6035FFF1FF77F8E16F60FE1B	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		MagnoliaPress via Plazi	Collado, Gonzalo A.;Galleguillos, Fernando F.	Collado, Gonzalo A., Galleguillos, Fernando F. (2025): A new species of? Diploctenium (Anthozoa: Meandrinidae) from the Trihueco Formation (Lower Paleocene), south-central Chile. Zootaxa 5584 (2): 281-287, DOI: 10.11646/zootaxa.5584.2.8, URL: https://doi.org/10.11646/zootaxa.5584.2.8
