Facies (2005) 51: 233–241 DOI 10.1007/s10347-005-0023-3

ORIGINAL PAPER

Wolfgang Kiessling · Eugenio Aragon´ · Roberto Scasso · Martin Aberhan · Jurgen¨ Kriwet · Francisco Medina · Diego Fracchia Massive corals in siliciclastic sediments of Chubut (Argentina)

Received: 23 December 2004 / Accepted: 17 February 2005 / Published online: 19 October 2005 C Springer-Verlag 2005

Abstract A horizon with large, massive corals in growth Introduction position was discovered in the Paleocene, probably upper , part of the Maastrichtian–Paleocene Lefipan´ For- The mass extinction at the end of the has mation of Chubut (Patagonia, Argentina). All corals belong affected most groups of marine . However, to one species, the cosmopolitan Haimesiastraea conferta significant variation exists between the extinction rates Vaughan, which survived the end-Cretaceous mass of different taxonomic groups. Scleractinian corals were extinction. The occurrence of massive corals at this site surprisingly little affected by the mass extinction and is exceptional both because of the siliciclastic depositional even many corals inferred to have hosted zooxanthellae regime and because of the high palaeolatitude setting. (photosymbiotic algae) in their tissues survived this An unusual autecology of this coral and strongly reduced event Kiessling and Baron-Szabo (2004). Here we report sedimentation rates, were probably the prerequisites for an unexpected occurrence of large and massive corals, coral growth, but a link to palaeoclimate is less likely. identified as Haimesiastraea conferta Vaughan, (1900) in coarse siliciclastic sediments of Paleocene age. This Keywords Bioerosion . Corals . Ecology . Mass discovery sheds light on the autecology of an important extinction . Paleocene . Siliciclastics survivor of the end-Cretaceous mass extinction.

W. Kiessling () · M. Aberhan Institut fur¨ Palaontologie,¨ Museum fur¨ Naturkunde, Geological setting and stratigraphy Humboldt-Universitat¨ Berlin, Invalidenstr. 43, The corals occur in the uppermost part of the Lefipan´ D-10115 Berlin, Germany e-mail: [email protected] Formation, the upper unit of a thick, siliciclastic sequence Tel.: +49-30-2093-8576 composed of the Paso del Sapo and Lefipan´ Formations, Fax: +49-30-2093-8868 exposed along the Middle Chubut River Valley near the town of Paso del Sapo (Fig. 1). The Lefipan´ Formation E. Aragon´ Centro de Investigaciones Geologicas,´ Universidad Nacional de is capped by continental beds and rests conformably on La Plata 1 No 644, a thick sequence of cross-bedded sandstones with some 1900 La Plata, Argentina coal beds and mudstones (Paso del Sapo Formation) of Campanian–Maastrichtian age (Fig. 2). The whole · R. Scasso F. Medina sequence is unconformably overlain by a volcanic– Departamento de Ciencias Geologicas,´ FCEN, Universidad de Buenos Aires, Ciudad Universitaria, pyroclastic complex, the Ignimbrita Barda Colorada Pab. 2, 1◦ Piso, (IBC) of the Middle Chubut River volcanic–pyroclastic 1428 Buenos Aires, Argentina complex (Aragon´ and Mazzoni 1997). K/Ar analyses of tuffs from the IBC have indicated a Late Paleocene age J. Kriwet 40 39 Department fur¨ Geo- und Umweltwissenschaften, (Archangelsky 1974). More recent K/Ar and Ar/ Ar Ludwig-Maximilians-Universitat¨ Munchen,¨ analyses of associated tuffs and volcanic rocks have Richard-Wagner-Str. 10, indicated a Late Paleocene to Middle age for the D-80333 Munchen,¨ Germany complex (Mazzoni et al. 1991; Wilf et al. 2003). D. Fracchia The Lefipan´ Formation is composed of marine, fossil- Instituto de Geolog´ıa y Mineria, Universidad Nacional de Jujuy, iferous sandstones and mudstones with some intercalated C. Correo 258, coquinas and conglomerates, and ranges from the 4600 S.S. de Jujuy, Argentina Maastrichtian to the Paleocene. The biostratigraphic 234

Fig. 1 Geographic and geological setting of the Lefipan´ Formation and location of coral-bearing outcrops

Formation, evolving to deltaic systems in the middle and upper part of the unit (Olivero and Medina 1994). Field studies of our working group on a reference sec- tion (San Ramon) and several partial sections in the area suggest that the lower part of the Lefipan´ Formation (Maastrichtian) was mainly deposited in a shallow marine, shoreface environment with strong tidal influence and a conspicuous association of trace fossils (Poire´ and Spalletti 1998) and beds rich in phosphatic concretions (Pereira and Scasso 2002). The palaeoenvironment evolved to a tide- to wave-dominated deltaic system in the middle part of the sequence, which comprises the Cretaceous–Paleogene boundary (Ruiz and Scasso 2004). In the Paleocene, the en- Fig. 2 Schematic geological column of exposed rocks near Paso vironment was deepening, developing into a fully marine del Sapo. Stratigraphic position of the coral locality at Estancia system influenced by wave and storm activity. Don Manuel is indicated. Not to scale. Camp - Campanian; Maa - Maastrichtian; Pal - Paleocene; Eoc - Eocene resolution is currently exclusively based on assemblages of Coral localities bivalves and gastropods and is therefore quite coarse. Three macrofossil assemblages have been separated in previous We have measured and studied several sections in the papers, one in the Maastrichtian and two in the Paleocene Lefipan´ Formation in the area, but corals have been found (Medina et al. 1990; Medina and Olivero 1994). The depo- at only two localities. Previous workers, with the exception sitional environment in the latest Cretaceous changes from of one (Camacho 1967), have not reported on the presence a fluvial to tidally influenced estuarine environment (Paso of corals in the area. At both our localities (Estancia Don del Sapo Formation) to an open marine environment in the Manuel in the Barda Colorado region and an unnamed lo- Lower Lefipan´ Formation (Spalletti 1996). Macrofossils cality in the upper part of the San Ramon section), corals and sedimentary features indicate a shallow marine or occur in a single horizon belonging to the Paleocene part estuarine environment for the lower part of the Lefipan´ of the Lefipan´ Formation. 235 Estancia Don Manuel (Barda Colorado) gressive Systems Tract) capped by the hardground repre- senting the maximum flooding surface. Horizons 4 and 5 Abundant corals were discovered in the Barda Colorado are preliminarily interpreted as early highstand deposits. area at a locality called Estancia Don Manuel (DM; A total of 52 mature coral colonies were found at this 42◦4350S, 69◦5838W). The Lefipan´ Formation in the locality in our 2004 expedition, with up to 60 cm maxi- Barda Colorado area is strongly folded and thrusted. Only mum diameter. The majority of corals were found in scree. parts of the unit are exposed, often in blocks separated by However, several massive corals occur in outcrop as well, thrust planes. As a consequence, the stratigraphic relation- where they are all in growth position forming a biostromal ships between the coral locality and the rest of the Lefipan´ layer. This layer is up to 50 cm thick and can be laterally Formation and to the overlying pyroclastics belonging to traced for 20 m (Fig. 4A and B). Corals found in outcrop the IBC complex are not completely clear. The DM locality (horizon 3) are irregular massive or hemispherical and are is apparently situated near the top of the Lefipan´ Formation. up to 50 cm in diameter and up to 30 cm high (Fig. 4B). From base to top, the sedimentary sequence at this locality One of the authors (EA) has found a dome-shaped coral- is (Fig. 3): lum of 80 cm height in a previous visit to the outcrop. All corals are identified as H. conferta Vaughan (Fig. 5A–H), 1. Brown, friable, mottled (intensely bioturbated) fine a species ranging from the Maastrichtian to the Middle sandstone typical of Lefipan´ Formation. Eocene. The corals are exclusively massive exhibiting do- 2. Conglomerates with interbedded sandstones. Conglom- mal, hemispherical or irregular growth forms (Table 1). The erate with 50% of clasts made of well-rounded gravel smallest, complete adult corallum is hemispherical with a up to 1 cm in diameter, fragmented bioclasts (bivalves diameter of 7 cm. and gastropods). The sandstone matrix has carbonate ce- The corals are moderately well preserved. Most of the ment. Intercalated are two sandstone layers the lower of corals are superficially little affected by bioerosion and which shows hummocky cross-bedding. This group of encrustation. Encrusting bivalves are small (Fig. 4G) and beds is capped by a hardground marked by reddish mud- cover less than 5% of the coral surfaces. Serpulids were also stones infilling borings and encrustations of serpulids found as encrusters, but there are no traces of encrusting and oysters. Gastropods (Turritella malaspina), bivalves algae. We have identified the bioerosion ichnogenera Gas- (Venericardia feruglioi, Pseudolimea sp. and Pycn- trochaenolites, Trypanites and Entobia in the corals. The in- odonte miradonensis), crustacean remains and shark tensity of bioerosion is apparently stronger than visible ex- teeth have been identified in the conglomerates immedi- ternally because most of the cavities are internal (Fig. 4F). ately below the hardground, suggestive of a Paleocene, Internal cavities tend to be aligned with coral growth struc- perhaps Danian age. The hardground is developed on an tures and are thus interpreted as passive “borings”, formed erosive surface. by the attachment of organisms to the live coral surface 3. Fossiliferous reddish conglomerate with large coral leading to local growth inhibition of the coral skeleton colonies in growth position. Impregnated sandstone peb- (Scoffin and Bradshaw 2000). Less than 10% of the coral bles up to 4 cm in maximum diameter occur in the bed. volume has apparently been excavated by active bioerosion, 4. Greenish sandstone, locally well-cemented. which is surprisingly little considering the high nutrient lev- 5. Red mudstone. els Zubia and Peyrot-Clausade (2001) that can be inferred 6. Unwelded tuff. for this inshore siliciclastic environment. Rapid burial of The coarse-grained beds of unit 2 can be interpreted as the corals by siliciclastic shedding was probably responsi- shoreface deposits, marking a transgressive sand (Trans- ble for the scarcity of post-mortem active bioerosion. The in situ preservation of corals is remarkable given the high energy environment. Sandstone pebbles up to 2 cm in diameter are attached to the flanks of domal colonies (Fig. 4E). The pebbles are impregnated by iron-oxides. They are preferentially attached to depressions formed by bioerosion but also accumulated in pits formed by physical erosion. The corals grew on a hardground (Fig. 4C), marked in places by reddish carbonate mudstones infilling large bore- holes. The borings mostly stem from bivalves, but other organisms such as worms and sponges were also involved. The hardground is locally encrusted by oysters and ser- pulids, and corals grew directly on this hardground. At one place juvenile corals have been found on the hardground (Fig. 6). Although not all distinctive characters are devel- oped, these corals are also assignable to H. conferta.We have analyzed an area of 250 cm2 in detail to understand the Fig. 3 Detailed local section of the outcrop at Estancia Don Manuel (weathering profile). Numbers correspond to the description in text mode of larval settlement and development. Most of these juvenile corals are solitary. Out of 58 juvenile corallites, 236

Fig. 4 Macroscopic features of the coral locality at Estancia Don Camera cap for scale (4 cm). D Small coral fragment in the coral Manuel and its corals (A–C, E–G), and coral in the San Ramon section bed of the San Ramon section, probably a Cladocora sp. Width of (D). A Overview of the outcrop Don Manuel. Geologists are at level picture is 1.5 cm. E One of the largest dome-shaped H. conferta of the coral bed. Layered mountain in the background is ignimbrite found in our 2004 expedition. Length of ruler is at 30 cm. Note large of the IBC complex. B One of the largest Haimesiastraea found gravel attached to the flank of the corallum. F Polished slab of a in growth position. Massive irregular growth form (outlined). Note dome-shaped corallum. Note external and intense internal bioero- internal bioerosion (white arrows) and encrusting bivalves (black ar- sion (outlined) filled with coarse sandstone and gravel (stippled) and rows). Camera cap for scale (4 cm). C Cross-section of hardground external mechanical erosion (outlined in white); centimetre scale. G as found in the field. The sandstone is heavily bored by bivalves Upper surface of corallum with encrusting juvenile oyster (arrow); and worms (?). Borings (outlined with white line) are filled with red centimetre scale calcareous mudstone and mudstone is encrusted by oysters (arrow). 237

Fig. 5 Details of H. conferta Vaughan from the outcrop at Es- corallum. E Cross-section showing details of costate coenosteum and tancia Don Manuel. A Tip of dome-shaped corallum; centimetre dissepiments in calice. F Detail of a corallite showing 12 septa of the scale. B Close-up of unprepared coral surface; centimetre scale. C first two cycles uniting in centre. G Detail of septothecate wall and Cross-section with internal bioerosion (note geopetal fabric). Unusu- the third septal cycle. H Detail of a septum exhibiting rudimentary ally large corallite on upper right. D Tangential section near base of lateral projections 238

Table 1 Growth forms of H. Domal Hemispherical Irregular massive conferta at Estancia Don Manuel Small (7–10 cm) Large (11–30 cm) N 65420 Based on 35 nearly complete Percentage 17 14 11 57 corals

fragments are identified as H. conferta and one is a dendroid form, possibly a Cladocora (Fig. 4D).

Stratigraphic correlation

Based on several observations, we correlate the coral out- crop at DM with the upper part of our reference section at San Ramon.´ First, based on mollusc assemblages both occurrences belong to faunal “Asociacion´ III” of Medina et al. (1990) indicative of the second faunal association within the Paleocene of the region. Second, we have found only one level with corals in both sections although we have studied the San Ramon´ section in detail over a thick- ness of 300 m. Third, the sequence stratigraphic position is identical in both occurrences. The carbonate nodules and intense fragmentation of shells point to reduced sedimen- Fig. 6 Incipient colonization of hardground by corals (cf. H. con- tation rates at San Ramon´ as does the hardground at DM. ferta) at Estancia Don Manual. Note patchiness of distribution of Fourth, both occurrences are associated with hummocky coral recruits and predominance of solitary forms. Size of surface ca. cross-stratification and lack the heterolithic bedding, which 20 cm × 14 cm. Inset shows details of juvenile corallites (millimetre is very common in the rest of the section. scale in lower right) The precise stratigraphic assignment of our coral locali- ties has to remain open at this point, because palynological only 21 (36%) were found in series showing evidence of studies have not provided unequivocal results so far early clonal growth. The majority of corallites shows fully (V. Barreda, personal communication, 2003) and other developed septal cycles just as the mature corallites in the microfossils are virtually absent. Based on macrofossils massive colonies. The immaturity of the corals suggests that (gastropods and bivalves), the age is certainly Paleocene they were killed off soon after larval settlement. Although and probably Late Danian. Haimesiastraea itself is of we cannot detail the time involved in the ontogenesis of this limited stratigraphic value. The oldest records of the extinct species, neontological studies suggest that colonial are from the Middle Cretaceous (Squires 1958), corals start budding a few days to several months after lar- the youngest known record is from the Middle Eocene val settlement (Babcock et al. 2003; Neves and da Silveira of Mexico (Frost and Langenheim 1974). H. conferta has 2003). The mass mortality of coral recruits, perhaps within a more limited range from the Campanian–Maastrichtian the first year after larval settling, supports the view that (Peru: Wells 1941; Argentina: Baron-Szabo in press) to the successful recruitment may be limited by sediment loads Middle Eocene (Mexico). The acme in terms of the number (Te 1992) and indicates harsh environmental conditions of occurrences and geographic distribution was in the Pa- during coral growth. It was only the second (at least) gen- leocene when H. conferta reached from central Patagonia eration of recruits which successfully developed into large (this study) to North America and Europe (Drobne et al. colonies. 1988). Most well-dated occurrences of H. conferta in the more recent literature are from the Danian (Toulmin 1977; San Ramon´ section Turnsekˇ and Drobne 1998; Baron-Szabo et al. 2003) and several of the occurrences formerly assigned to the Middle In the San Ramon´ section only three coral fragments were and Late Eocene have been reassigned to the Paleocene– found in a bed at 42◦4111S, 69◦5017W, close to the Early Eocene (Floris 1972). This contrasts the opinion top of our measured section. The bed is composed of a of Budd (2000) who sees Haimesiastraea essentially glauconitic sandstone with abundant carbonate nodules and confined to the Middle Eocene of the Caribbean. shell hash. Similar to Estancia Don Manuel, the bed is un- derlain by hummocky cross-bedded sandstones and over- lain by sandy mudstones. Gastropods (Pseudamaura dubia, Discussion Struthioptera sp.) and bivalves (Venericardia sp., Meretrix chalcedonica) are common in the bed and serpulids, crab The occurrence of corals is not unusual in the Paleocene of remains, shark teeth and corals are rare. Two of the coral Argentina. Corals were recorded from Puelen,´ La Pampa 239 (Baron-Szabo et al. 2003), Huantraico and Bajada del minimum rates observed for modern healthy Montastrea Jaguel¨ (own unpublished data), Neuquen´ and Tierra del annularis; see Dullo 2005), we achieve a live span of the Fuego (Furque and Camacho 1949). These findings include largest colony in our material of 160 years. The death of massive corals in Puelen´ and Huantraico but none of the the successful coral recruits was apparently caused by re- massive corals are so closely associated with coarse sili- newed rapid sedimentation. Rapid burial is inferred from ciclastic sediments. Moreover, in none of these localities the scarcity of encrustation and the in situ preservation of have such large colonies been found and the other places corals. are quite distant from our locality. An open question remains the exclusively massive growth The discovery of such large and massive coral colonies of our corals, although H. conferta has the plasticity for and in a purely siliciclastic shelf setting was completely unex- commonly exhibits ramose growth (Vaughan 1900; Wells pected and we know of no similar occurrence in the fossil 1941; Frost and Langenheim 1974). Since vertical accre- record. tion rates of corals with ramose growth are usually greater It was apparently the transient sediment starvation asso- than in massive corals (compare growth rates of modern ciated with a flooding surface that allowed for the growth Acropora and Montastrea; Dullo 2005), one would expect of corals. There must have been little or no sedimenta- ramose growth as an escape strategy from sedimentation tion over a prolonged interval of time to first stabilize the stress in this siliciclastic setting. Indeed observations in substrate and then permit the corals to reach these large di- modern and corals suggest that massive colonies mensions. Our observations point to at least two successive often achieve a branching growth form where siliciclas- colonization episodes, the first unsuccessful and the second tic sedimentation is enhanced (Nose and Leinfelder 1997; successful. Constraints on the duration of coral growth are Sanders and Baron-Szabo 2005). difficult to reconstruct without further data on their ecol- Palaeoclimate does not seem to be a major trigger of coral ogy. Specifically, we need to know if H. conferta was a development. The best palaeoclimatic data for the area are zooxanthellate or azooxanthellate coral. from Early Eocene plant associations in the Tufolitas La- Although not included in the list of Paleocene z-like guna del Hunco, which indicate a mean annual temperature (zooxanthellate-like, meaning likely to have hosted zoox- of 15.6 ± 2◦C and an overall warming trend of 6◦C(∼12 anthellae in their tissue) of Rosen (2000), many morpho- to 18◦C) within the Ypresian based on leaf-margin anal- logical characters of Haimesiastraea point to a z-like status, ysis (Wilf et al. 2003). There is little information on the applying the criteria of Coates and Jackson (1987): large earlier climatic history of the study area. However, global size of corallum, small size of corallites, multiserial ar- data suggest a continuous warming trend from the Middle rangement of corallites and moderately high integration of Paleocene to the Late Ypresian (Zachos et al. 2001). Ac- corallites. cording to our preliminary stratigraphic assignments, the The geographic and environmental distribution of corals occur before the onset of this warming trend and Haimesiastraea suggests that the genus was cosmopolitan, thus temperature, at least as inferred from global data, are opportunistic and able to thrive in siliciclastic settings. probably not directly related to their occurrence. Haimesiastraea is known from palaeotropical regions (Peru) to very high palaeolatitudes (Greenland, palaeolat- itude 62◦N, Floris 1972; this study, palaeolatitude 45◦S) Conclusion and occurs in carbonate platforms and reefs (Drobne et al. 1988; Tragelehn 1996), coarse siliciclastics (Floris 1972; Abundant massive colonies of H. conferta occurring in the this study) and even claystones (Wasem and Wilbert 1943). Paleocene of the Lefipan´ Formation permit insights into These traits are untypical for z-like taxa and this was the the autecology of an important Paleocene coral species. reason why Kiessling and Baron-Szabo (2004) qualified H. conferta had a peculiar autecology allowing it to thrive Haimesiastraea as az-like (azooxanthellate-like, meaning in a variety of habitats and a wide geographic range. unlikely to have hosted zooxanthellae in their tissue). Morphological characters and estimated growth rates However, no modern az-coral is even distantly similar identify H. conferta as a zooxanthellate-like coral, but it in size and morphology to Haimesiastraea. Moreover, in apparently had substantially broader physiological niche spite of its great environmental tolerance, Haimesiastraea boundaries than most modern zooxanthellate corals. This has exclusively been recorded in shallow water settings sug- was perhaps the reason why this species could survive the gesting light as a prerequisite for coral growth. We there- end-Cretaceous mass extinction. fore argue that H. conferta hosted zooxanthellae in its tissue and had calcification rates comparable to modern massive corals. The stress imposed by sedimentation may have re- Systematic palaeontology duced skeletal growth rates (Hudson et al. 1994; Miller and Cruise 1995) but not necessarily so (Edinger et al. 2000). The coral material is deposited in the Museum of La Plata That there was stress by contemporaneous sedimentation (Argentina) under the inventory number MLP 31305. can be inferred from the scarcity of active bioerosion, which Order: Scleractinia (Bourne, 1900) is typical for environments with high siliciclastic shedding Suborder: Faviina (Vaughan and Wells 1943) (Sanders and Baron-Szabo 2005). With a reasonable es- − Family: Columastreidae (?) (Alloiteau 1952) timate of vertical accretion rates (5 mm year 1, e.g., the 240 Genus: Haimesiastraea Vaughan (1900) The suprageneric classification of Haimesiastraea is con- Type species (by original designation): Haimesiastraea troversial. No family assignment was provided by Vaughan conferta Vaughan (1900) (1900); Felix (1925) has assigned the genus to the Astro- Haimesiastraea conferta Vaughan (1900) coeniidae, Wells (1941) to the Haimesiastraeidae, Wells Figs. 4B, E–G, 5, 6 (1956) and Budd et al. (1992) to the Stylinidae and Frost ∗1900 Haimesiastraea conferta, sp. nov. - Vaughan, pp and Langenheim (1974) to the Acroporidae. The most re- 145–146, pl. 15, Figs. 6–9, pl. 16, Figs. 1–7; [Late cent classification scheme grouped Haimesiastraea with Paleocene–Early Eocene, Alabama] the Columastreidae (Baron-Szabo in press) based on the 1922 Peruviastrea peruviana, Vaughan, sp. n. - Vaughan presence of pali and columella. in Bosworth, p 129, pl. 21, Figs. 6, 6a,7,7a; [Paleocene–Early Eocene, Peru] 1922 Haimesiastraea peruviana, Vaughan, sp. n. - Description (based on 11 thin sections from three corals) Vaughan in Bosworth, p 130, pl. 22, Figs. 2–2b; [Paleocene–Early Eocene, Peru] One corallum domal, 30 cm in vertical and up to 25 cm in 1922 Haimesiastraea humilis, Vaughan, sp. n. - Vaughan horizontal dimension; the others irregular massive. Coral- in Bosworth, p 131, pl. 22, Figs. 3, 3a,4,4a; lites plocoid to almost cerioid with subcircular calices, 1.3– 3.1 mm in maximum diameter (mean = 1.86 mm, median [Paleocene–Early Eocene, Peru] = 1922 Haimesiastraea distans, Vaughan, sp. n. - Vaughan 1.8 mm, based on 42 measurements). Budding extraten- in Bosworth, p 132, pl. 22, Figs. 5, 5a; [Paleocene– tacular. Corallites united by an open meshwork of costae, Early Eocene, Peru] corresponding to all cycles of the septa, and linked by tab- 1922 Haimesiastraea conferta, Vaughan, - Vaughan in ular exothecal dissepiments forming the coenosteum. Dis- Bosworth, pp 125, 131, pl. 22, Figs. 1, 1a tance between corallites (smallest distance between coral- 1933 Haimesiastraea conferta, Vaughan - Vaughan and lite walls) 0.45–0.7 mm. Popenoe, pp 338–339, pl. 4, Figs. 1–2; [Paleocene, Septa in three cycles, thin, thickening towards the wall. Texas] First two cycles of septa reaching into the centre of calices. 1941 Montastrea parinasensis, n. sp. - Wells, p 7 (307), Internal margins of these 12 septa fusing, to form a tra- pl. 1, Fig. 2; [Maastrichtian, Peru] becular to substyliform columella. Septal margins entire, 1941 Haimesiastraea distans, Vaughan - Wells, p 15 sometimes with rudimentary lateral projections (Fig. 5H), (315), pl. 2, Fig. 4; [Paleocene–Early Eocene, Peru] inner ends somewhat thickened and bent (Fig. 5E). Paliform lobes present, indistinct. Third cycle of septa incomplete 1941 Peruviastrea peruviana, Vaughan - Wells, p 16 > (316), pl. 2, Fig. 5; [Paleocene–Early Eocene, Peru] in small corallites but complete in larger ones ( 1.8 mm 1943 Haimesiastraea conferta, Vaughan - Wasem and diameter of calice). Microstructure not well preserved. Me- Wilbert, pl. 31, Fig. 3; [Late Paleocene, Louisiana] dian lines in septa distinct in cross-section (Fig. 5F), no 1974 Haimesastraea (Haimesastraea) peruviana, calcification centres visible. Endothecal dissepiments rare, Vaughan - Frost and Langenheim, pp 193–194, pl. 59, tabular. Figs. 1–5; [Middle Eocene, Mexico] 1977 Haimesastraea conferta, Vaughan - Toulmin, pp Comparison 145, 182, pl. 1, Fig. 7, pl. 10, Figs. 9–10; [Danian, Alabama] The DM corals agree in nearly all details with the original 1988 Haimesastraea peruviana, Vaughan - Drobne, description of H. conferta of Vaughan (1900). The only Ogorelec, Plenicar, Zucchi-Stolfa and Turnsek,ˇ p 186, notable difference is that endothecal dissepiments are pl. 30, Fig. 3; [Danian, Slovenia] usually rare in our material but were indicated as very 1996 Hexakoralle, Morphotyp 18. - Tragelehn, p 198, pl. abundant by Vaughan (1900). In this respect and in the 62, Figs. 8–9; [Paleocene, Austria] substyliform columella, our corals agree with the diagnosis 1998 Haimesastraea peruviana, Vaughan, 1922 - of Peruviastrea Vaughan. However, because there are Turnsekˇ and Drobne, pp 134–135, pl. 3, Fig. 1; [Danian, both trabecular and substyliform types of columella in Slovenia] the same colonies, we agree with Wells (1941) that the styliform type is probably the result of diagenetic changes. Following the detailed discussion of Frost and Langenheim (1974) and the observations of Baron-Szabo (in press), General remarks we have consequently synonymized several species of Haimesiastraea and Peruviastrea. Vaughan described the coral as Haimesiastraea, and it was known under this name until it was misspelled as Haime- Acknowledgments Research on the KT boundary in Patagonia is sastraea in the Treatise (Wells 1956). Since then, the cor- supported by the Deutsche Forschungsgemeinschaft (DFG, Ki 806- rect genus name has only been used by Floris (1972).We 1), the Antorchas Foundation (Republica´ Argentina) and the Euro- pean Community program “Improving Human Research Potential recommend using the original name of Vaughan (1900). and the Socio-Economic Knowledge Base”. We thank Rosemarie A complete synonymy list including all citations in the Baron-Szabo for advice regarding the taxonomic status of H. con- literature is provided by Baron-Szabo (in press). ferta, and Lucas Ruiz and Sven Weidemeyer for assistance in the field. 241

References Neves EG, da Silveira FL (2003) Release of planula larvae, settlement and development of Siderastrea stellata Verrill, 1868 (Anthozoa, Scleractinia). Hydrobiologia 501:139–147 Aragon´ E, Mazzoni MM (1997) Geolog´ıa y estratigraf´ıa del com- Nose M, Leinfelder RR (1997) Upper Jurassic coral communities plejo volcanico-pirocl´ astico´ del R´ıo Chubut medio´ (Eoceno). within siliciclastic settings (Lusitanian Basin, Portugal), Rev Asoc Geol Argent 52:243 implications for symbiotic and nutrient strategies. Proc 8th Int Archangelsky S (1974) Sobre una edad de la flora del Hunco, Coral Reef Symp 2:1755–1760 Provincia de Chubut. Ameghiniana 11:413–417 Olivero EB, Medina FA (1994) Sedimentolog´ıa de la Formacion´ Babcock RC, Baird AH, Piromvaragorn S, Thomson DP, Willis Lefipan´ (Cretacico-Terciario)´ en el valle medio del R´ıo Chubut. BL (2003) Identification of scleractinian coral recruits from Rev Asoc Geol Argent 48:105–106 Indo-Pacific reefs. Zool Stud 42:211–226 Pereira DM, Scasso RA (2002) Procedencia de las areniscas Baron-Szabo RC Corals of the K/T-boundary. Part 1: Scleractinian fosfaticas´ de la Formacion Lefipan, valle medio del R´ıo Chubut, corals of the suborders Astrocoeniina, Faviina, Rhipidogyrina, Provincia del Chubut. 15◦ Congr Geol Argent Actas 1:684–689 and Amphiastraeina. Syst Palaeont 3 (in press) Poire´ DG, Spalletti LA (1998) Trace fossil shallowing-upwards Baron-Szabo RC, Casad´ıo S, Parras A (2003) First shallow water stacking pattern of high-order progradational sequences: an scleractinian coral reef from the Danian, northern Patagonia, example from the Cretaceous–Tertiary of western Patagonia, Argentina. Ameghiniana Supl 40:79R Argentina. AAPG Annu Convent, Abst 2 A527:1–4 Bosworth TO (1922) Geology of the Tertiary and Quaternary periods Rosen BR (2000) Algal symbiosis, and the collapse and recovery in the north-west part of Peru. MacMillan, London, pp 434 of reef communities: Lazarus corals across the K-T boundary. Budd AF (2000) Diversity and extinction in the Cenozoic history of In: Culver SJ, Rawson PF (eds) Biotic response to global Caribbean reefs. Coral Reefs 19:25–35 change: the last 145 million years. Cambridge University Press, Budd AF, Stemann TA, Stewart RH (1992) Eocene Caribbean Cambridge, pp 164–180 reef corals: a unique fauna from the Gatuncillo Formation of Ruiz L, Scasso RA (2004) Analisis´ paleoambiental de la Formacion´ Panama. J Paleont 66:570–594 Lefipan´ en el entorno del l´ımite K/T de la Provincia de Chubut. Camacho HH (1967) Consideraciones sobre una fauna del Cretacico´ X Reun Argent Sediment San Luis Actas 198–199 superior (Maestrictiano) del Paso del Sapo, curso medio del r´ıo Sanders D, Baron-Szabo RC (2005) Scleractinian assemblages Chubut. Ameghiniana 5:131–134 under sediment input: their characteristics and relation to the Coates AC, Jackson JBC (1987) Clonal growth, algal symbiosis, nutrient input concept. Palaeogeogr Palaeoclimatol Palaeoecol and reef formation by corals. Paleobiology 13:363–378 216:139–181 Drobne K, Ogorelec B, Plenicar M, Zucchi-Stolfa MK, Turnsekˇ D Scoffin TP, Bradshaw C (2000) The taphonomic significance (1988) Maastrichtian, Danian and Thanetian beds in Dolenja of endoliths in dead - versus live - coral skeletons. Palaios vas (NW Dinarides, Yugoslavia). Microfacies, foraminifers, 15:248–254 rudists and corals. Razprave IV, Razreda Sazu 29:147– Spalletti LA (1996) Estuarine and shallow-marine sedimentation in 224 the Upper Cretaceous-Lower Tertiary west-central Patagonian Dullo W-Chr (2005) Coral growth and reef growth: a short review. Basin (Argentina). In: de Batist M, Jacobs P (eds) Geology of Facies 51 (this volume) siliciclastic shelf seas. Geol Soc Spec Publ, London 117:81–93 Edinger EN, Limmon GV, Jompa J, Widjatmoko W, Heikoop JM, Squires DF (1958) The Cretaceous and Tertiary corals from New Risk MJ (2000) Normal coral growth rates on dying reefs: are Zealand. N Z Geol Surv, Palaeont Bull 29:1–107 coral growth rates good indicators of reef health? Mar Pollut Te FT (1992) Response to higher sediment loads by Pocillopora Bull 40:404–425 damicornis planulae. Coral Reefs 11:131–134 Felix J (1925) Anthozoa eocaenica et oligocaenica. Foss Cat Toulmin LD (1977) Stratigraphic distribution of Paleocene and I/28:1–296 Eocene fossils in the eastern Gulf Coast region. Geol Surv Floris S (1972) Scleractinian corals from the Upper Cretaceous and Alabama Monogr 13:1–601 Lower Tertiary of Nugssuaq, West Greenland. Medd Gronland Tragelehn H (1996) Maastricht und Palaoz¨ an¨ am Sudrand¨ der 196:1–132 Nordlichen¨ Kalkalpen (Niederosterreich,¨ Steiermark) - Fazies, Frost SH, Langenheim RL Jr (1974) Cenozoic reef biofacies. Stratigraphie und Fossilfuhrung¨ des ’Kambuhelkalkes’¨ und Northern Illinois University Press, Chicago, pp 388 assoziierter Sedimente. Ph.D. thesis, Univ Erlangen, pp 216 Furque G, Camacho HH (1949) El cretaceo superior de la costa Turnsekˇ D, Drobne K (1998) Paleocene corals from the northern Atlantica de Tierra del Fuego. Rev Asoc Geol Argent 4:263– Adriatic Platform. Dela Opera SAZU IV 34:129–154 297 Vaughan TW (1900) The Eocene and lower coral faunas Hudson JH, Hanson KJ, Halley RB, Kindinger JL (1994) Envi- of the United States with descriptions of a few doubtfully ronmental implications of growth rate changes in Montastrea Cretaceous species. US Geol Surv Monogr 39:1–263 annularis—Biscayne National Park, Florida. Bull Mar Sci Vaughan TW, Popenoe WP (1933) The coral fauna of the Midway 54:647–669 Eocene of Texas. Univ Texas Bull 3301:325–343 Kiessling W, Baron-Szabo R (2004) Extinction and recovery patterns Wasem R, Wilbert LJ Jr (1943) Pendleton Formation, Louisiana and of scleractinian corals at the Cretaceous–Tertiary boundary. Texas. J Paleont 17:181–195 Palaeogeogr Palaeoclimatol Palaeoecol 214:195–223 Wells JW (1941) Cretaceous and Eocene corals from Peru. Bull Mazzoni MM, Kawashita K, Harrison S, Aragon´ E (1991) Amer Paleont 26:304–326 Edades radiometricas´ Eocenas. Borde occidental del Macizo Wells JW (1956) Scleractinia. In: Moore RC (ed) Treatise on Norpatagonico.´ Rev Asoc Geol Argent 46:150 invertebrate paleontology. Part F, Coelenterata. Geol Soc Amer, Medina FA, Olivero EB (1994) Paleontolog´ıa de la Formacion´ Univ Kansas Press, Lawrence, pp F328–F444 Lefipan´ (Cretacico-Terciario)´ en el Valle medio del R´ıo Chubut. Wilf P, Cuneo´ NR, Johnson KR, Hicks JF, Wing SL, Obradovich JD Rev Asoc Geol Argent 48:104 (2003) High plant diversity in Eocene South America: evidence Medina FA, Camacho HH, Malagnino EC (1990) Bioestratigraf´ıa from Patagonia. Science 300:122–125 del Cretacico´ superior-Paleoceno marino de la Formacion´ ◦ Zachos J, Pagani M, Sloan L, Thomas E, Billups K (2001) Trends, Lefipan.´ Barranca de los Perros, R´ıo Chubut. 5 Congr Argent rhythms, and aberrations in global climate 65 Ma to present. Paleont Bioestratigr Actas 7:137–142 Science 292:686–693 Miller RL, Cruise JF (1995) Effects of suspended sediments on Zubia M, Peyrot-Clausade M (2001) Internal bioerosion of Acropora coral growth—Evidence from remote sensing and hydrologic formosa in Reunion (Indian Ocean): microborer and macroborer modeling. Remote Sensing Environ 53:177–187 activities. Oceanol Acta 24:251–262