Pub Date : 2026-06-01Epub Date: 2026-01-21DOI: 10.1016/j.cretres.2026.106317
Vladimir N. Makarkin
The subfamily Cretanallachiinae is elevated to a family level, Cretanallachiidae, stat. nov. Its autapomorphies are bipectinate antennae in males and a long ventro-caudal extension of the 9th tergite in females. The family is known only from mid-Cretaceous Kachin amber. It is likely closely related to Dilaridae, an undescribed ithonoid-like taxon from the Middle Jurassic, and to a lesser extent Ithonidae. They lived in humid tropical forests with diverse angiosperms and probably fed on their flowers (nectar and/or pollen) using relatively long sucking mouthparts.
{"title":"Cretanallachiidae – a new family of the specialized Cretaceous Neuroptera","authors":"Vladimir N. Makarkin","doi":"10.1016/j.cretres.2026.106317","DOIUrl":"10.1016/j.cretres.2026.106317","url":null,"abstract":"<div><div>The subfamily Cretanallachiinae is elevated to a family level, Cretanallachiidae, stat. nov. Its autapomorphies are bipectinate antennae in males and a long ventro-caudal extension of the 9th tergite in females. The family is known only from mid-Cretaceous Kachin amber. It is likely closely related to Dilaridae, an undescribed ithonoid-like taxon from the Middle Jurassic, and to a lesser extent Ithonidae. They lived in humid tropical forests with diverse angiosperms and probably fed on their flowers (nectar and/or pollen) using relatively long sucking mouthparts.</div></div>","PeriodicalId":55207,"journal":{"name":"Cretaceous Research","volume":"182 ","pages":"Article 106317"},"PeriodicalIF":1.7,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147385521","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-06-01Epub Date: 2026-01-13DOI: 10.1016/j.cretres.2026.106313
Joel Crothers , Jaelyn Eberle , Donald Brinkman , Alyssa Wurtz , Andrew B. Heckert , ReBecca K. Hunt-Foster , John R. Foster , Ida C. Dirkes , Renee Dunn
The Williams Fork Formation (WFF) of northwestern Colorado preserves an understudied freshwater biota from the Campanian/Maastrichtian boundary. Here we describe a diverse actinopterygian-dominated fish assemblage from the ReBecca's Hollow locality of Rio Blanco County. Chondrichthyans are rare from this site, but include a hybodontid, Lonchidion, and the hemiscyllid Chiloscyllium. A fragmentary element may represent a pycnodontiform. Chondrosteans are represented by a tentative acipenserid. Holosteans include the lepisosteids Atractosteus and an unnamed taxon, and the amiids Melvius, Cyclurus and Palaeolabrus. Teleosteomorphs at this site include Belonostomus, Paralbula casei, Coriops, Estesesox foxi, Acronichthys, hiodontids, and acanthomorphs. This locality yields at least 17 fish taxa, most of which have not been described previously from the WFF. Although the WFF is temporally correlative with the St. Mary River and Horseshoe Canyon Formations in Alberta and the Prince Creek Formation in Alaska, the ReBecca's Hollow fish assemblage is markedly different from its northern contemporaries. Specifically, it contains several warm-climate taxa such as Lonchidion, Chiloscyllium, Melvius, Atractosteus, and Paralbula, and lacks higher latitude taxa such as Holostean A, documented from Alberta. The differences in these broadly contemporaneous fish assemblages supports the hypothesis that there was provincialism amongst freshwater fishes in Laramidia at the Campanian/Maastrichtian boundary. The fish fauna thus resembles that of Campanian localities in Utah, New Mexico, and Texas, and Maastrichtian (Lancian) localities in Montana, North Dakota, South Dakota, and Wyoming, suggesting that the boundary between these provincial zones remained north of the WFF locality throughout these periods of climate change.
{"title":"An actinopterygian-dominated fish fauna from the Upper Cretaceous Williams Fork Formation, northwestern Colorado, and evidence for provinciality across Laramidia at the Campanian/Maastrichtian boundary","authors":"Joel Crothers , Jaelyn Eberle , Donald Brinkman , Alyssa Wurtz , Andrew B. Heckert , ReBecca K. Hunt-Foster , John R. Foster , Ida C. Dirkes , Renee Dunn","doi":"10.1016/j.cretres.2026.106313","DOIUrl":"10.1016/j.cretres.2026.106313","url":null,"abstract":"<div><div>The Williams Fork Formation (WFF) of northwestern Colorado preserves an understudied freshwater biota from the Campanian/Maastrichtian boundary. Here we describe a diverse actinopterygian-dominated fish assemblage from the ReBecca's Hollow locality of Rio Blanco County. Chondrichthyans are rare from this site, but include a hybodontid, <em>Lonchidion</em>, and the hemiscyllid <em>Chiloscyllium</em>. A fragmentary element may represent a pycnodontiform. Chondrosteans are represented by a tentative acipenserid. Holosteans include the lepisosteids <em>Atractosteus</em> and an unnamed taxon, and the amiids <em>Melvius</em>, <em>Cyclurus</em> and <em>Palaeolabrus</em>. Teleosteomorphs at this site include <em>Belonostomus</em>, <em>Paralbula casei</em>, <em>Coriops</em>, <em>Estesesox foxi</em>, <em>Acronichthys</em>, hiodontids, and acanthomorphs. This locality yields at least 17 fish taxa, most of which have not been described previously from the WFF. Although the WFF is temporally correlative with the St. Mary River and Horseshoe Canyon Formations in Alberta and the Prince Creek Formation in Alaska, the ReBecca's Hollow fish assemblage is markedly different from its northern contemporaries. Specifically, it contains several warm-climate taxa such as <em>Lonchidion</em>, <em>Chiloscyllium</em>, <em>Melvius</em>, <em>Atractosteus</em>, and <em>Paralbula</em>, and lacks higher latitude taxa such as Holostean A, documented from Alberta. The differences in these broadly contemporaneous fish assemblages supports the hypothesis that there was provincialism amongst freshwater fishes in Laramidia at the Campanian/Maastrichtian boundary. The fish fauna thus resembles that of Campanian localities in Utah, New Mexico, and Texas, and Maastrichtian (Lancian) localities in Montana, North Dakota, South Dakota, and Wyoming, suggesting that the boundary between these provincial zones remained north of the WFF locality throughout these periods of climate change.</div></div>","PeriodicalId":55207,"journal":{"name":"Cretaceous Research","volume":"182 ","pages":"Article 106313"},"PeriodicalIF":1.7,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146071113","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-06-01Epub Date: 2026-01-12DOI: 10.1016/j.cretres.2025.106307
Lucas N. Lerzo
The sauropod fauna of the Upper Cretaceous of Patagonia is dominated by large titanosaurs and medium to large-sized rebbachisaurids. Particularly, rebbachisaurid sauropods dominated the Cenomanian-Turonian of Patagonia. Specimen MMCh-PV 47, which includes 10 middle to posterior caudal vertebrae and haemal arches, was recovered from the Candeleros Formation of Villa El Chocón, Neuquén, Argentina, and was formerly described as a titanosaur sauropod. On the base of the amphicoelous centra with the posterior articular surface more concave than the anterior one, the placement of the neural arch close to the anterior margin of the centrum, the ventral longitudinal hollow, and middle haemal arches with a stellated morphology, the specimen MMCh-PV 47 is instead considered within Rebbachisauridae. A phylogenetic analysis recovered it in a basal clade with Sidersaura, Campananeyen, Zapalasaurus, Astigmasaura and specimen MACN-Pv-N-35. This basal clade is characterized by the presence of middle haemal arches exhibiting two set of anterior and posterior projections, one on the proximal rami and another on the distal blade. In lateral view, the first six caudal vertebrae of the specimen MMCh-PV 47 exhibit rugose surfaces on the dorsal end of the centrum, indicating that the M. caudofemoralis longus extends much further posterior than in other sauropods. Laterodorsally projected ventral bar of the transverse processes, and the development of the haemal arches would increase the surface of attachment for the M. caudofemoralis longus, being a muscle of greater functional significance compared to other sauropod clades.
巴塔哥尼亚上白垩纪蜥脚类动物群以大型泰坦龙和中、大型雷巴奇龙为主。尤其是巴塔哥尼亚的塞诺曼尼亚-土尔onian， rebbachisaurid蜥脚类占优势。标本MMCh-PV 47，包括10个中后侧尾椎骨和血液弓，从阿根廷neuqu的Villa El Chocón的Candeleros地层中发现，以前被描述为泰坦龙蜥脚类动物。以后关节面较前关节面凹的双掌中央为基础，神经弓靠近椎体前缘，腹侧纵向凹陷，中间血弓呈星形形态，MMCh-PV 47标本被认为属于Rebbachisauridae科。系统发育分析发现其与Sidersaura、Campananeyen、Zapalasaurus、Astigmasaura和标本MACN-Pv-N-35属于一个基支。这个基部分支的特征是存在中间的血弓，表现出两组前后突出，一组在近支，另一组在远端。从侧面看，标本MMCh-PV 47的前六块尾椎骨在椎体的背端呈现出皱纹表面，表明尾状长尾椎骨比其他蜥脚类动物向后延伸得更远。尾部长肌横向突起的腹侧横突和血液弓的发育会增加附着面，与其他蜥脚类动物相比，尾部长肌具有更大的功能意义。
{"title":"Revision of the specimen MMCh-PV 47 (Rebbachisauridae, Sauropoda) from the Candeleros Formation (lower Cenomanian) with comments about the musculature of the caudal region","authors":"Lucas N. Lerzo","doi":"10.1016/j.cretres.2025.106307","DOIUrl":"10.1016/j.cretres.2025.106307","url":null,"abstract":"<div><div>The sauropod fauna of the Upper Cretaceous of Patagonia is dominated by large titanosaurs and medium to large-sized rebbachisaurids. Particularly, rebbachisaurid sauropods dominated the Cenomanian-Turonian of Patagonia. Specimen MMCh-PV 47, which includes 10 middle to posterior caudal vertebrae and haemal arches, was recovered from the Candeleros Formation of Villa El Chocón, Neuquén, Argentina, and was formerly described as a titanosaur sauropod. On the base of the amphicoelous centra with the posterior articular surface more concave than the anterior one, the placement of the neural arch close to the anterior margin of the centrum, the ventral longitudinal hollow, and middle haemal arches with a stellated morphology, the specimen MMCh-PV 47 is instead considered within Rebbachisauridae. A phylogenetic analysis recovered it in a basal clade with <em>Sidersaura</em>, <em>Campananeyen</em>, <em>Zapalasaurus</em>, <em>Astigmasaura</em> and specimen MACN-Pv-N-35. This basal clade is characterized by the presence of middle haemal arches exhibiting two set of anterior and posterior projections, one on the proximal rami and another on the distal blade. In lateral view, the first six caudal vertebrae of the specimen MMCh-PV 47 exhibit rugose surfaces on the dorsal end of the centrum, indicating that the <em>M. caudofemoralis longus</em> extends much further posterior than in other sauropods. Laterodorsally projected ventral bar of the transverse processes, and the development of the haemal arches would increase the surface of attachment for the <em>M. caudofemoralis longus</em>, being a muscle of greater functional significance compared to other sauropod clades.</div></div>","PeriodicalId":55207,"journal":{"name":"Cretaceous Research","volume":"182 ","pages":"Article 106307"},"PeriodicalIF":1.7,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147385522","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-06-01Epub Date: 2026-01-21DOI: 10.1016/j.cretres.2026.106316
V.S. Perez Loinaze , N. Ortiz Ruffinelli , R. Rodriguez , M. Cevallos
Palynomorph assemblages were recovered from the “Neocomian deposits” and the Pozo D-129 Formation in the VOA.SC.CL.a-4005 well, Golfo San Jorge Basin, Argentina. The studied palynofloras comprise 67 spore species, 26 pollen taxa and, one algal taxon. Based on the presence of Densoisporites corrugatus, a Barremian age is proposed for the “Neocomian deposits”. Likewise, a Barremian age is inferred for the analyzed levels of the Pozo D-129 Formation, supported by the occurrence of Cicatricosisporites hughesii, Cyatheacidites tectifera, and Densoisporites corrugatus. This age assignment is further supported by a chronostratigraphic correlation with the Barremian tectifera-corrugatus Interval Zone of southern Patagonia. Multivariate statistical analysis comparing the studied assemblages with other Lower Cretaceous palynofloras from Patagonia reveal strong similarities with assemblages from the Las Heras Group and the Puesto Albornoz Formation, thereby confirming previous regional correlations. Overall, this study contributes to a more detailed understanding of the paleofloras and depositional history of the Golfo San Jorge Basin.
在VOA.SC.CL的“新comian矿床”和Pozo D-129组中发现了孢藓组合。阿根廷Golfo San Jorge盆地a-4005井所研究的孢粉区系包括67个孢子种、26个花粉分类群和1个藻类分类群。根据瓦楞纸岩的存在，提出了“新第三纪沉积”的巴雷米亚时代。同样地，通过出现Cicatricosisporites hughesii、Cyatheacidites tectifera和Densoisporites gatus，可以推断出Pozo D-129组的巴雷米期年龄。与巴塔哥尼亚南部巴雷米亚断层-瓦楞层带的年代地层对比进一步支持了这一年龄分配。通过多元统计分析，将所研究的组合与巴塔哥尼亚其他下白垩统孢粉植物进行比较，发现与Las Heras组和Puesto Albornoz组的组合具有很强的相似性，从而证实了之前的区域相关性。总体而言，该研究有助于更详细地了解圣乔治湾盆地的古植物区系和沉积历史。
{"title":"Palynostratigraphic analysis of lower Cretaceous sediments in the Golfo San Jorge Basin, central Patagonia, Argentina","authors":"V.S. Perez Loinaze , N. Ortiz Ruffinelli , R. Rodriguez , M. Cevallos","doi":"10.1016/j.cretres.2026.106316","DOIUrl":"10.1016/j.cretres.2026.106316","url":null,"abstract":"<div><div>Palynomorph assemblages were recovered from the “Neocomian deposits” and the Pozo D-129 Formation in the VOA.SC.CL.a-4005 well, Golfo San Jorge Basin, Argentina. The studied palynofloras comprise 67 spore species, 26 pollen taxa and, one algal taxon. Based on the presence of <em>Densoisporites corrugatus</em>, a Barremian age is proposed for the “Neocomian deposits”. Likewise, a Barremian age is inferred for the analyzed levels of the Pozo D-129 Formation, supported by the occurrence of <em>Cicatricosisporites hughesii</em>, <em>Cyatheacidites tectifera</em>, and <em>Densoisporites corrugatus</em>. This age assignment is further supported by a chronostratigraphic correlation with the Barremian <em>tectifera-corrugatus</em> Interval Zone of southern Patagonia. Multivariate statistical analysis comparing the studied assemblages with other Lower Cretaceous palynofloras from Patagonia reveal strong similarities with assemblages from the Las Heras Group and the Puesto Albornoz Formation, thereby confirming previous regional correlations. Overall, this study contributes to a more detailed understanding of the paleofloras and depositional history of the Golfo San Jorge Basin.</div></div>","PeriodicalId":55207,"journal":{"name":"Cretaceous Research","volume":"182 ","pages":"Article 106316"},"PeriodicalIF":1.7,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147385524","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-05-01Epub Date: 2025-11-18DOI: 10.1016/j.cretres.2025.106264
Renata Juliana Arruda Maia , Enelise Katia Piovesan , Santana Holes Pereira De , Robbyson Mendes Melo , Lima Filho Mario Ferreira De , Rodolfo Dino , Luzia Antonioli
This work aims to expand knowledge of the taxonomy of ostracods from the Lower Cretaceous of Northeast Brazil, with an emphasis on the association recovered from wells in the Codó Formation of the Parnaíba and São Luís basins, integrating foraminiferal assemblages and facies analyses to refine paleoenvironmental interpretations. The results provided input for expanding biostratigraphic correlations based on ostracods and paleoenvironmental interpretations based on ostracods, foraminifera association, and facies analysis. For this work, samples were recovered from three wells: 2-ANP-5-MA, drilled in the São Luís Basin, and 1-FSS08-GJ and 9-PIF-16-MA, drilled in the Parnaíba Basin. The methodology included weighing, washing, drying, and sorting samples, followed by imaging and taxonomic identification. The dominant ostracods genera were Pattersoncypris Bate, Reconcavona Krömmelbein, and Cypridea Bosquet. Two new species were proposed: Pattersoncypris inflata and Ilyocypris tryponata. Identifying the guide species P. micropapillosa (Biozone OST-011) made it possible to position the samples in the Aptian, Lower Cretaceous. Benthic foraminifera specimens, representing nine genera and eleven taxa, were recovered from core 1-FSS08-GJ. The most abundant foraminifera genera are Bathysiphon and Rhizammina. From the integrated analysis of the association between carbonate microfossils and facies, it was possible to confirm the occurrence of marine influence during the Aptian in the Codó Formation, Parnaíba Basin.
本研究旨在扩大巴西东北部下白垩统介形类的分类知识，重点研究Parnaíba和 o Luís盆地Codó组井的关联，结合有孔虫组合和相分析来完善古环境解释。研究结果为扩展介形类的生物地层对比以及基于介形类、有孔虫组合和相分析的古环境解释提供了输入。在这项工作中，从3口井中回收了样品：在 o Luís盆地钻探的2-ANP-5-MA，以及在Parnaíba盆地钻探的1-FSS08-GJ和9-PIF-16-MA。方法包括称重、洗涤、干燥和分选样品，然后进行成像和分类鉴定。优势介形虫属为pattersoncypriis Bate、Reconcavona Krömmelbein和Cypridea Bosquet。提出了2个新种：膨龙鲤（Pattersoncypris inflata）和锥鱼鲤（ilycypris tryponata）。通过对该样品的鉴定，使其定位于下白垩统阿普tian地区。在1-FSS08-GJ岩心共采集到底栖有孔虫9属11类群。最丰富的有孔虫属是深孔虫和根孔虫。通过对碳酸盐岩微化石与相的综合分析，可以确定Parnaíba盆地Codó组Aptian期存在海相影响。
{"title":"Integrated biostratigraphic and paleoenvironmental framework of Aptian ostracods and foraminifera from the Codó Formation (Parnaíba and São Luís Basins, Northeast Brazil)","authors":"Renata Juliana Arruda Maia , Enelise Katia Piovesan , Santana Holes Pereira De , Robbyson Mendes Melo , Lima Filho Mario Ferreira De , Rodolfo Dino , Luzia Antonioli","doi":"10.1016/j.cretres.2025.106264","DOIUrl":"10.1016/j.cretres.2025.106264","url":null,"abstract":"<div><div>This work aims to expand knowledge of the taxonomy of ostracods from the Lower Cretaceous of Northeast Brazil, with an emphasis on the association recovered from wells in the Codó Formation of the Parnaíba and São Luís basins, integrating foraminiferal assemblages and facies analyses to refine paleoenvironmental interpretations. The results provided input for expanding biostratigraphic correlations based on ostracods and paleoenvironmental interpretations based on ostracods, foraminifera association, and facies analysis. For this work, samples were recovered from three wells: 2-ANP-5-MA, drilled in the São Luís Basin, and 1-FSS08-GJ and 9-PIF-16-MA, drilled in the Parnaíba Basin. The methodology included weighing, washing, drying, and sorting samples, followed by imaging and taxonomic identification. The dominant ostracods genera were <em>Pattersoncypris</em> Bate, <em>Reconcavona</em> Krömmelbein, and <em>Cypridea</em> Bosquet. Two new species were proposed: <em>Pattersoncypris inflata</em> and <em>Ilyocypris tryponata</em>. Identifying the guide species <em>P. micropapillosa</em> (Biozone OST-011) made it possible to position the samples in the Aptian, Lower Cretaceous. Benthic foraminifera specimens, representing nine genera and eleven taxa, were recovered from core 1-FSS08-GJ. The most abundant foraminifera genera are <em>Bathysiphon</em> and <em>Rhizammina</em>. From the integrated analysis of the association between carbonate microfossils and facies, it was possible to confirm the occurrence of marine influence during the Aptian in the Codó Formation, Parnaíba Basin.</div></div>","PeriodicalId":55207,"journal":{"name":"Cretaceous Research","volume":"181 ","pages":"Article 106264"},"PeriodicalIF":1.7,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145694934","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-05-01Epub Date: 2025-11-20DOI: 10.1016/j.cretres.2025.106266
Camille Frau
The revision of the heteromorph ammonite Anisoceras carcitanense Matheron, 1880, supports the establishment of the new genus Hourqueigella gen. nov. Its suture line, characterized by a very deep, symmetrically trifid adventive lobe and a broad, bipartite lateral saddle, together with medium-sized hamulicone coiling featuring an extended retroversum and simple ribbing, indicates close affinities with certain members of the family Acrioceratidae Vermeulen, particularly the atuberculate pole of Toxoceratoides, previously assigned to the Tonohamites–Raymondcaseyites plexus. The combination of exceptionally large size, hamulicone coiling, and hypermorphic retroversum in Hourqueigella, however, demonstrates a clear generic distinction from these atuberculate Toxoceratoides. Examination of new topotype specimens from Cassis–Roquefort-La-Bédoule, southern France, confirms the presence of this species in the lower upper Aptian (lower Epicheloniceras martini Zone).
异形菊石Anisoceras carcitanense Matheron（1880）的修正支持了Hourqueigella gen. 11新属的建立，其缝合线的特征是非常深的对称的三裂外生裂片和宽的两裂侧鞍，以及中等大小的环形盘曲，具有延伸的后背和简单的肋，表明与Vermeulen family的某些成员有密切的关系。特别是弓形虫的管状极，以前属于托诺哈米特-雷蒙德卡塞基神经丛。然而，在Hourqueigella中，异常大的体型、假体盘绕和超形态的后足的组合表明了与这些疣状弓形虫的明显的一般区别。对来自法国南部cassis - roquefort - la - b doule的新形态标本的检查证实，该物种存在于阿普tian的下上部（下Epicheloniceras martini区）。
{"title":"A revision of the lower cretaceous heteromorphic ammonite species Anisoceras carcitanense Matheron, 1880 and the introduction of Hourqueigella gen. nov.","authors":"Camille Frau","doi":"10.1016/j.cretres.2025.106266","DOIUrl":"10.1016/j.cretres.2025.106266","url":null,"abstract":"<div><div>The revision of the heteromorph ammonite <em>Anisoceras carcitanense</em> Matheron, 1880, supports the establishment of the new genus <em>Hourqueigella</em> gen. nov. Its suture line, characterized by a very deep, symmetrically trifid adventive lobe and a broad, bipartite lateral saddle, together with medium-sized hamulicone coiling featuring an extended retroversum and simple ribbing, indicates close affinities with certain members of the family Acrioceratidae Vermeulen, particularly the atuberculate pole of <em>Toxoceratoides</em>, previously assigned to the <em>Tonohamites–Raymondcaseyites</em> plexus. The combination of exceptionally large size, hamulicone coiling, and hypermorphic retroversum in <em>Hourqueigella</em>, however, demonstrates a clear generic distinction from these atuberculate <em>Toxoceratoides</em>. Examination of new topotype specimens from Cassis–Roquefort-La-Bédoule, southern France, confirms the presence of this species in the lower upper Aptian (lower <em>Epicheloniceras martini</em> Zone).</div></div>","PeriodicalId":55207,"journal":{"name":"Cretaceous Research","volume":"181 ","pages":"Article 106266"},"PeriodicalIF":1.7,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145749459","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-05-01Epub Date: 2025-11-29DOI: 10.1016/j.cretres.2025.106273
María Paula Iglesia Llanos , Diego A. Kietzmann , Ricardo I.F. Trindade , Janine Araújo do Carmo , Daniele Brandt , João Pedro Rodriguez-Pinto
A high-resolution chronostratigraphic study was conducted on one of the best-exposed sections of the Vaca Muerta Formation in the Neuquén Basin, west-central Argentina, spanning the Upper Jurassic to Lower Cretaceous. The Puerta Curaco section (∼360 m thick) records a rhythmic succession of mudstones, marlstones, limestones, and tuffs deposited on a carbonate ramp system rich in ammonites. Sixty paleomagnetic horizons were sampled and integrated with biostratigraphy (ammonites and calpionellids), magnetostratigraphy, and cyclostratigraphy in order to establish a robust chronostratigraphic framework. The analysis of paleomagnetic components was combined with rock magnetism studies to characterize magnetic mineralogy and define a reliable polarity sequence. The resulting magnetostratigraphic scale comprises 13 normal (N1–N13) and 13 reverse (R1–13) polarity zones for the Tithonian–Berriasian. Mean site directions define two distinct populations, one for the Tithonian, and other for the Berriasian, both passing field tests (i.e., fold test) and confirming a primary magnetic remanence. Cyclostratigraphic calibration of polarity zones, together with Andean–Tethyan ammonite correlations allowed the section to be tied to the Geomagnetic Polarity Time Scale (GPTS, 2020), extending across Chrons M22 to M15. The Tithonian paleomagnetic pole (81.3°S, 112.5°E; α95 = 4.4°) falls on the Late Jurassic segment of the South American apparent polar wander path, whereas the Berriasian–Valanginian paleopole (76.0°S, 53.7°E; α95 = 3.2°) is interpreted as rotated.
{"title":"Magnetostratigraphy and cyclostratigraphy of the Vaca Muerta Formation (Upper Jurassic–Lower Cretaceous) at Puerta Curaco, Neuquén, Argentina","authors":"María Paula Iglesia Llanos , Diego A. Kietzmann , Ricardo I.F. Trindade , Janine Araújo do Carmo , Daniele Brandt , João Pedro Rodriguez-Pinto","doi":"10.1016/j.cretres.2025.106273","DOIUrl":"10.1016/j.cretres.2025.106273","url":null,"abstract":"<div><div>A high-resolution chronostratigraphic study was conducted on one of the best-exposed sections of the Vaca Muerta Formation in the Neuquén Basin, west-central Argentina, spanning the Upper Jurassic to Lower Cretaceous. The Puerta Curaco section (∼360 m thick) records a rhythmic succession of mudstones, marlstones, limestones, and tuffs deposited on a carbonate ramp system rich in ammonites. Sixty paleomagnetic horizons were sampled and integrated with biostratigraphy (ammonites and calpionellids), magnetostratigraphy, and cyclostratigraphy in order to establish a robust chronostratigraphic framework. The analysis of paleomagnetic components was combined with rock magnetism studies to characterize magnetic mineralogy and define a reliable polarity sequence. The resulting magnetostratigraphic scale comprises 13 normal (N1–N13) and 13 reverse (R1–13) polarity zones for the Tithonian–Berriasian. Mean site directions define two distinct populations, one for the Tithonian, and other for the Berriasian, both passing field tests (i.e., fold test) and confirming a primary magnetic remanence. Cyclostratigraphic calibration of polarity zones, together with Andean–Tethyan ammonite correlations allowed the section to be tied to the Geomagnetic Polarity Time Scale (GPTS, 2020), extending across Chrons M22 to M15. The Tithonian paleomagnetic pole (81.3°S, 112.5°E; α<sub>95</sub> = 4.4°) falls on the Late Jurassic segment of the South American apparent polar wander path, whereas the Berriasian–Valanginian paleopole (76.0°S, 53.7°E; α<sub>95</sub> = 3.2°) is interpreted as rotated.</div></div>","PeriodicalId":55207,"journal":{"name":"Cretaceous Research","volume":"181 ","pages":"Article 106273"},"PeriodicalIF":1.7,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145749461","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this work, 47 isolated small theropod teeth from different microsites of “El Gallo” Formation, Baja California, Mexico are studied. Isolated theropod teeth constitute important evidence to analyse theropod diversity, since they are quite common in the fossil record. For their identification, we conducted morphological comparisons using multivariate and cladistic analyses comparing them with previously described small theropod teeth from Upper Cretaceous North America Formations. This dental material can be assigned mainly to two families: Dromaeosauridae, Troodontidae; and one subfamily: Saurornitholestinae. Also, some of the teeth were assigned to Richardoestesia and two specimens were indeterminate. Dromaeosaurids represent the most abundant group of theropods in “El Gallo” followed by the Richardoestesia dental Morphotype. This diversity pattern is similar to the one reported in the Aguja Formation of Texas for the same period of time. The use of multivariate statistical techniques and cladistic analyses allowed us to evaluate the similarity between specimens, however, taxonomical assignments are difficult due to the lack of knowledge of intraspecific morphological and/or ontogenetic variation that can lead to misinterpretations. Even so, the sample of 47 specimens yields valuable information that allows suggesting the presence of certain taxa and providing knowledge of the diversity of the continental Cretaceous fauna in Mexico.
{"title":"Isolated teeth of small theropods from the El Gallo Formation, Baja California, Mexico","authors":"Vanessa Alexandra García-Gil , Angélica Torices , Mirella López-Miguel , Marisol Montellano-Ballesteros","doi":"10.1016/j.cretres.2025.106292","DOIUrl":"10.1016/j.cretres.2025.106292","url":null,"abstract":"<div><div>In this work, 47 isolated small theropod teeth from different microsites of “El Gallo” Formation, Baja California, Mexico are studied. Isolated theropod teeth constitute important evidence to analyse theropod diversity, since they are quite common in the fossil record. For their identification, we conducted morphological comparisons using multivariate and cladistic analyses comparing them with previously described small theropod teeth from Upper Cretaceous North America Formations. This dental material can be assigned mainly to two families: Dromaeosauridae, Troodontidae; and one subfamily: Saurornitholestinae. Also, some of the teeth were assigned to <em>Richardoestesia</em> and two specimens were indeterminate. Dromaeosaurids represent the most abundant group of theropods in “El Gallo” followed by the <em>Richardoestesia</em> dental Morphotype. This diversity pattern is similar to the one reported in the Aguja Formation of Texas for the same period of time. The use of multivariate statistical techniques and cladistic analyses allowed us to evaluate the similarity between specimens, however, taxonomical assignments are difficult due to the lack of knowledge of intraspecific morphological and/or ontogenetic variation that can lead to misinterpretations. Even so, the sample of 47 specimens yields valuable information that allows suggesting the presence of certain taxa and providing knowledge of the diversity of the continental Cretaceous fauna in Mexico.</div></div>","PeriodicalId":55207,"journal":{"name":"Cretaceous Research","volume":"181 ","pages":"Article 106292"},"PeriodicalIF":1.7,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145840982","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-05-01Epub Date: 2025-12-07DOI: 10.1016/j.cretres.2025.106283
Ryoko Matsumoto , Makoto Manabe , Susan E. Evans
The extinct reptilian group Choristodera has been recorded from the Lower Cretaceous Tetori Group of Japan. Within the Tetori Group, the Okurodani Formation was the first deposit to yield choristoderan remains with the discovery of the postcranial skeleton of the long-necked Shokawa ikoi. Howerver, until now, the formation has yielded only limited choristoderan material. Here, we report on several further choristodere remains, including the finding of an unexposed skull element during a μCT examination of the holotype of Shokawa ikoi. Although the new specimens are all isolated elements, detailed comparison has revealed that they represent an unexpected diversity of taxa including a long-snouted neochoristodere, a non-neochoristodere with an open lower temporal fenestra, and a possible new monjurosuchid. Similarities between the choristoderan assemblages of the Jehol Biota of China and the Tetori Group of Japan have previously been recognised. However, the new choristoderan records from the Okurodani Formation albeit fragmentary, suggest possible differences in assemblage composition, and add to our knowledge of choristoderan diversity in eastern Asia at a key stage in their evolutionary history.
{"title":"Cranial elements of Shokawa ikoi, and new records of choristoderes from the Lower Cretaceous Okurodani Formation, Tetori Group, Japan","authors":"Ryoko Matsumoto , Makoto Manabe , Susan E. Evans","doi":"10.1016/j.cretres.2025.106283","DOIUrl":"10.1016/j.cretres.2025.106283","url":null,"abstract":"<div><div>The extinct reptilian group Choristodera has been recorded from the Lower Cretaceous Tetori Group of Japan. Within the Tetori Group, the Okurodani Formation was the first deposit to yield choristoderan remains with the discovery of the postcranial skeleton of the long-necked <em>Shokawa ikoi.</em> Howerver, until now, the formation has yielded only limited choristoderan material. Here, we report on several further choristodere remains, including the finding of an unexposed skull element during a μCT examination of the holotype of <em>Shokawa ikoi.</em> Although the new specimens are all isolated elements, detailed comparison has revealed that they represent an unexpected diversity of taxa including a long-snouted neochoristodere, a non-neochoristodere with an open lower temporal fenestra, and a possible new monjurosuchid. Similarities between the choristoderan assemblages of the Jehol Biota of China and the Tetori Group of Japan have previously been recognised. However, the new choristoderan records from the Okurodani Formation albeit fragmentary, suggest possible differences in assemblage composition, and add to our knowledge of choristoderan diversity in eastern Asia at a key stage in their evolutionary history.</div></div>","PeriodicalId":55207,"journal":{"name":"Cretaceous Research","volume":"181 ","pages":"Article 106283"},"PeriodicalIF":1.7,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145840981","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-05-01Epub Date: 2025-12-02DOI: 10.1016/j.cretres.2025.106255
Pablo Suarez-Gonzalez , I. Emma Quijada , Ramón Mas , M. Isabel Benito , Eugenia Arribas , José Arribas , Sonia Campos-Soto
Aurell et al. (2021; Cretaceous Research, vol. 128, 104997) studied Lower Cretaceous deposits from the Torrelapaja Subbasin, a relatively small area to the SE of the Cameros Basin (N Spain), making new sedimentological and stratigraphic interpretations. They used those interpretations to establish correlations of the entire Cameros Basin with other basins, inferring palaeogeographic reconstructions of NE Iberia. This comment shows that some of their interpretations are not fully supported by their data and arguments, or that they can be qualified with data published before their article. This comparison with previous data shows that Aurell et al. (2021) provided an inaccurate view of the regional literature, which resulted in the misleading idea that their palaeogeographic interpretations were more novel than they actually are.
{"title":"Comment on Aurell et al. (2021) “Latest Jurassic-early Cretaceous synrift evolution of the Torrelapaja Subbasin (Cameros Basin): Implications for Northeast Iberia palaeogeography”. Cretaceous Research 128 (104997)","authors":"Pablo Suarez-Gonzalez , I. Emma Quijada , Ramón Mas , M. Isabel Benito , Eugenia Arribas , José Arribas , Sonia Campos-Soto","doi":"10.1016/j.cretres.2025.106255","DOIUrl":"10.1016/j.cretres.2025.106255","url":null,"abstract":"<div><div>Aurell et al. (2021; Cretaceous Research, vol. 128, 104997) studied Lower Cretaceous deposits from the Torrelapaja Subbasin, a relatively small area to the SE of the Cameros Basin (N Spain), making new sedimentological and stratigraphic interpretations. They used those interpretations to establish correlations of the entire Cameros Basin with other basins, inferring palaeogeographic reconstructions of NE Iberia. This comment shows that some of their interpretations are not fully supported by their data and arguments, or that they can be qualified with data published before their article. This comparison with previous data shows that Aurell et al. (2021) provided an inaccurate view of the regional literature, which resulted in the misleading idea that their palaeogeographic interpretations were more novel than they actually are.</div></div>","PeriodicalId":55207,"journal":{"name":"Cretaceous Research","volume":"181 ","pages":"Article 106255"},"PeriodicalIF":1.7,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145798617","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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